OK, we've avoided this long enough. Vents are pretty tricky to do and not to mention difficult. It has been a nightmare for me trying to figure out the best way to do them. This is only my method of doing them, there are other ways of doing them but this is the best I could come up with. Before you do anything, you might want to clone the rear door and hide the clone in case you mess up and want to try the vents again. This will save you the trouble of having to rebuild the whole door if you mess it up.
The first thing you should do is to add an "Edit Mesh" modifier on top of the "Meshsmooth" modifier that is on top of the stack. The Meshsmooth that is there should have 2 iterations on it. By doing this, everything that is below the new Edit Mesh modifier is now not going to be used so collapse the stack up to the new modifier you just added. This also means that the mesh is now permanently at a higher poly count and this is what we want to be able to do the vents. Don't worry about messing this up because you have a copy hidden as a backup. Now select the polys shown and detach them from the mesh as a new object called "Vent" or something to that effect.
Now hide the rest of the door and leave just the polys you just detached visible. Then put a "Meshsmooth" on this new object with 2 iterations. Once again, add an "Edit Mesh" modifier on top of the Meshsmooth you just added and then collapse the stack again. Now go into polygon mode and select the polys shown in red below. You should have nine rows of polys selected since there are going to be nine vents.
Now extrude these polys inwards a small distance and then with them still selected drag them straight up. Dragging them up makes the vents go upwards at an angle instead of straight in along the x-axis. Ok, now comes the really fun part! Unhide the rest of the door with the hole where the vent polys used to be. The vents still fit perfectly in the hole they left but because you smoothed the vent polys, there are now too many edges and they don't match up with the edges on the rest of the door. To fix this, you have to do some welding.........a lot of welding! Make sure edged faces are turned on in the viewports and then go into vertex mode and start moving vertices and welding them so that you have just enough vertices to match up with the vertices on the rest of the door. Then attach the vent polys to the rest of the door and weld the corresponding polys. Confused?!?! Understandable! The picture below should show what I mean. The green circles show where vertices were moved to and welded.
At this point you could leave this as it is or you could add another Meshsmooth to the door with one iteration. But if you do this, your mesh will become incredibly dense and slow your computer down. It's up to you what you do.
You can hide the rear door now and unhide the body of the car because you are now going to do the vents on the body. Make the cut shown below. Detach the polys shown and then hide the rest of the car.
There is a thin line of polys that was created by a previous chamfer that you don't need at the moment so weld the vertices in the green circle to remove the thin line of polys. You will redo the chamfer later.
Continuing the Vents
Extrude the edges shown to complete the box shape. Weld the 2 vertices in the green circle.
Now chamfer some edges to get sharper edges when smoothed. Mirror a copy of these polys and then attach the two halves and weld the vertices in the middle. You are going to work on this part as a whole shape and not just as a half because of the way the vents are arranged. Add a "Meshsmooth" modifier to the polys and set iterations to 4. This is a very high amount of smoothing and your computer might have trouble with it. You might try to do the same thing with 3 iterations but then you will have smaller number of vents which are bigger. Now add an "Edit Mesh" modifier on top of the "Meshsmooth" and go into polygon mode. Select the polys shown below. There should be 39 vents in total. Notice that the outermost vents on either side are a little shorter than the rest.
Now extrude these polys inwards a small distance and then bevel slightly inwards to create the vents. Now you can go in and chamfer around each vent or you can just leave them the way they are, that's up to you but just don't put anymore Meshsmooths on it or your computer will hate you forever! The next thing you need to do is to unhide the body of the car and fix the area where you detached the polys by doing some extrudes and chamfers so that the vents fit properly. You should have this:
Ok, the vents are now complete. Thank God for that! Since there is still some space on this page, I guess it wouldn't be a bad idea to do the license plates. These are very simple. Start with the back plate. Create a box primitive that fits in the plate indentation on the rear door. Chamfer edges as necessary to get this. Now you have to make it curved so that it fits perfectly on the back of the car. Just arrange vertices to get the desired curve.
The front plate is made pretty much the same way so I will leave you to do that. When you are done you should have something like this (The positioning of the front plate is up to you. It can be put above or below the front fender or even on the fender itself, it's a matter of preference.):
To create the wipers, it might be easier to do it in a new file so start a new file called "wiper.max". In the front viewport, create a cone primitive with the parameters shown below.
Now let's do some box modeling. Just select polys, extrude them and tweak vertices until you have something like this:
Now you have to do the wiper blade and it's holder, this is also not very hard. In the top viewport, create a small box and extrude and bevel it and give it some curvature. Also do some chamfering.
Now you can put whatever detail you want into the wiper. For this tutorial I ended up with what's shown below.
Next you need to do the water squirters for the wipers. These are just simple cylinders with nozzles like this:
Now you have to open your Fiat file and merge it with the wiper.max. Your Wiper and squirter will have to be resized to fit on the car and some vertex tweaking might be necessary. Duplicate the wiper and the squirter for the other side of the car.
The last accessory that I forgot all about is the driver side mirror. This is an optional accessory as some of the references I found did not have mirrors. They also come in different shapes so the shape you use is up to you. It's very easy to make so I'm not going to bore you with step by step instructions on how to make it. Below is a picture of my completed mirror.
This is what the car looks like now (Minus the mirror which I only remembered after these renders were done, hehehehe!!):
Well this is the end of the Trim and Accessories section of this tutorial. Next we will tackle the making of the tires.