Part 1: Modeling the Nissan R390 GT in 3ds max 5
>> Section 6: Detailing #2

Next step is cutting holes in the bonnet: there are 2 main air intakes and 4 smaller on both sides. Basically what i did was cut the mesh with the aid of the top blueprints, trying to get the contour of the hole. Then i cut it more and more tryin not to loose a basic quad structure. After i had the shape i needed, i just deleted the hole's polygon. After that i started moving vertices to get the shape as close as possible to the original, giving a bit of depth and a good roundness to the top edges. Look at Fig. 30 and Fig. 31 to see where and how i cut the mesh.
The other holes are done in a similar way, just cutting with the help of the blueprints, then tweaking the mesh with more cuts to keep it clean. In Fig. 32 and Fig. 33 you can see an overall view and a detailed view of the 4 new holes. Notice that the increased density in the mesh leads to some problems, as keeping the surface smooth is more difficult and you have to be sure vertices are well placed. Also notice that i made slight changes to the big hole are as well. This is normal in my workflow: i often notice areas to improve when i am rotating the model in the viewports to work on another area.

Now let's cut the front bumper to get the proper shape for the main air intakes: first i cut the mesh placing edges where the holes will be, then i selected the relevant polygons and extruded them inwards (in 2 steps so i get a sharper edge). After this, just select the inside polygons and delete them (always delete isolated vertices when asked). To create the horizontal bar i made use of the "connect" tool of the meshtools script. Basically you select 2 or more facing polygons, hit "connect" and you're done: a very handy and intuitive tool. You can see the result in Fig. 34.
The bumper also has 2 holes for the front "fog-lights". Getting a perfectly round shape here can be quite difficult. After you have made the basic hole (refer to Fig. 35 to see how i setup the mesh), place a cylinder inside it as a reference, activate NURMS subdivisions and try to get the shape as precise as you can, by moving vertices where needed. After this, build a half sphere, invert the normals and place it inside the holes. This will be the chrome reflecting part. You can also put another sphere inside or actually model the light bulb if you're a real maniac: i just put a sphere there, with all the reflections on going nobody will hopefully notice the difference!). Don't forget to cover the holes with a glass covering: i just used a chamfer cylinder (very thin) for this purpose. The final result (with NURMS on) is in Fig. 36.
I now switched back to the bonnet air intake: there are 4 small bars inside it. I tried to model them as a part of the bonnet mesh, using the "connect" meshtools option, but i didn't quite like the result i was getting. I reverted back to a previous save file and tried another way: i just made 4 chamfered boxes and placed them in the hole. Then i added 2 "bend" modifiers and tried to make them fit exactly. A test render was enough to confirm that this trick was working pretty good, so i thought: for now it's ok, if in the final image i get a bad result, i wil model them that day (which never arrived ;-)). Refer to Fig. 37 to see the result.

At this point i was ready to get to the back area and detail it. I spent some time on adding shape details to the mesh, using mainly the reference images i have (and they are not very good for the rear btw). After the usual cutting i got the mesh ready to receive holes for the 4 rear lights. The workflow is exactly the same as the front bumper: refer to Fig. 38 to see the final result. The rear lights are just easy chamfer cylinders with different materials and a "oil tank" primitive as the top: click here to see the rearlights.
I also cut the holes where the rear wing is mounted. The difficult part was to keep sharp corners (all 90°) on the borders: this was achieved by adding edges near the borders. Refer to Fig. 39 to see a detailed wireframe of the area, and check that you get the desired output by activating NURMS subdivisions.

The lower rear area is a bit weird in its shape, anyway it's quite easy to ahchieve the right look. Luckily i had a good outline from the starting spline, so i had to do a little work. Just make sure you make the vertices well aligned by looking from a side view, so you have a planar surface on the back of the surface. You can have a look at the wireframe here and atthe smoothed version here. (Images are not in the usual place because at first i forgot about this part :-P).

Time to add the side exhausts: this part of the car is quite complex, not even 100% clear from my references. There's a hole for the exhaust outlet, and there's another probably used as an air intake which brings down the exhaust temperature so it doesn't fuse the car's surface. Anyway, once i figured out in my mind how this part could be, i started by cutting the main hole and extruding it inward, as showed in Fig. 40. I then modeled the air intake as i could see it from the references: in Fig. 41 you can see the mesh after all the cutting and vertex adjusting. After modeling the 2 holes i meade the esxhaust duct by creating a cylinder, applying a bend modifier, converting to poly and extruding some rings of faces as shown in Fig. 42. In the same image you can see the exhaust's outlet (i started from a box, then selected the exterior face and started beveling it inward and bending it towards the exhaust tube) and another surface for the interior (just take a look at the image and everything should be pretty clear). In Fig. 43 you can see the smoothed area.

We are now ready for the wheels, which are luckily not to difficult (the rims are nice and easy to do with poly). Start by creating 2 concentric tubes with 40 sides and about 10/11 height segments for the outer one and 20 sides and 3 height segs for the inner one (Fig. 44). Convert them to poly. Pick the outer one tube, cut ring ("quickslice) on the outer side and extrude the external polygons to create the border. Then select all the inner polys except for 2 exernal rings and extrude them inside, getting the shape in Fig. 45. Then pick the inner tube, select polys as in Fig. 46 and bevel them once, then bevel them again till half of the outer tube radius. Now slect the edges 2 by to on the top of the newly extruded shapes and connect them creating 3 polygons on each top, and then bevel them a little (Fig. 47). Now create new polys on the outer tube by using the same procedure. Now you can select all the poly you need to connect the outer and inner tube (after attaching the 2 poly objects). Refer to Fig. 48 to see the result you should get. Now just add a disc brake (i recycled the one i did in Rhino for my Peugeot 206, anyway it's really easy to do one by extruding some circular splines), cap the inner tube on the inside (i just made a fitting cylinder, attached it and welded all the coincident verts), model a simple bolt and the tyre. To model the tyre i referred to the nice tutorial by Error404 (Daniel Buck) which you can read at http://www.danielbuck.net/tire_tut/tiretut.htm (i made slight changes in building the tyre but that doesn't really matter). Well done and easy to follow tutorial btw.

Another important part is the car door: it has a peculiar shape which at first i didn't notice. Giving the meshsmoothed door the right shape was not an easy task: i did this part by trial and error. The final mesh in itself is quitesimple, but having the right cuts in the right places was quite a pain. Anyway you can save some time by taking a look at the wireframe and the meshsmoothed version in Fig. 50 and Fig. 51. Also here i have to thank Laxina, a guy from CGtalk forum which really helped :-)

So, the main parts of the car are now finally done. We just need to add the final details and then we will be ready for Part II of this tutorial, texturing. I think now it would be a good idea to save your work for the 1st time and proceed to the next and final section :-P.