Rather than 3dsmax, what other programmes are there which can do pretty decent modelling, for free? Mapping is not essential.
Blender, get it from Blender.org, some things in it are better than in MAX, but be sure to google Blender keys cheat sheet also, it is not as menu driven as MAX even it has been improved, you still really need to use hotkeys as that is a lot easier and faster in a long run. However you can't currently make rFactor2 files with Blender, someone needs to make plugin to make that happen, but you can export .3ds files and many other type so one can then get files converted to rF2 with 3dsimed or max. Oh yes, 3dsimed is quite nice tool also, but it does costs you money, of course not as much as MAX, but still not free. It takes about a day or two to start getting hang of hotkeys in Blender, after that I found it being faster and somehow more fluent extension of arm than MAX when modelling (that little what I can do which is not much), texturing etc. can't comment, but it has tools in it, just haven't figured out them much yet.
As Nikos said, if you are currently a post-secondary student you can get a free copy of the various suites of current software offered by 3DS's parent company (forget the name at the moment), which includes 3DS. I think it also includes Alias. Now I forget who all is in that company! :S A decent alternative is Zmodeler. I used to use it a lot back in the SCGT days, and I still use the current version (zModeler 2) it from time to time for some really quick polygon exploration before jumping into CAD for work projects. Kind of a proof-of-concept type of workflow. Once you know how to use it, it's quite quick to work with. As polygon limits in games increase, though, I don't know how useful it'll be as I've never done anything in it other than draw one triangle at a time.
ZModeller is actually quite powerful once you get into using it. It uses nurbs as well as being able to perform many of the same tasks you can do with 3DS Max.
There is also gMax, which is a free lite version of 3DS Max. http://www.turbosquid.com/gmax Be sure to install the Tutorials for complete lessons on using it. They are a lot of fun, easy to understand and will teach you most everything you need to know to get going with it.
Yes, Autodesk has a student program. If you are not a student but know someone who is, you can ask them to make the account for you. I am not a student. However, my father was in the military and that also qualifies and therefore I was able to get a student version of every program that Autodesk offers. Keep in mind, though that these versions are NOT to be used for profit.
If I remember right the last version of gmax was from 5 or 6 years ago. Some people were asking ISI to get gmax support for rF1. It didnt work with very many games because autodesk wanted a lot of money from gamedevs(understandably so, since for making game models it was basicly the same as max from the same era). You were able to save models in a supported filetype then use other programs to convert to the one you need though.
3DTin < Free Wings 3D < Free Blender < Free Pixologic Sculptris < Free ZModeler 2/3 <$22 Silo <$159 Rhinoceros 3D <$195 LightWave 3D <$227 (EDU) Autodesk Entertainment Creation Suite Ultimate 2013 "Student" <$300 ..includes: Autodesk Maya Autodesk 3ds Max Autodesk Softimage EDIT: Apparently my old favourite, ZBrush is now also being used for things like vehicle modelling. $700, 50% students. Found ALL over the net....