Your assessment and analogy are incorrect. A more accurate analogy would be:
You go to a car company and pay money for a use license (rental) of a vehicle. In that rental agreement, it specifically states that no ownership of the vehicle is transfered to you (i.e. you are not buying the software) and it further states that you may NOT alter (change the source code) or sell the vehicle to anyone else (as you do not own any part of the vehicle). Your agreement only allows you to USE the software, not OWN it. Read your software license very closely.
If you do not like those restrictions on the software license, then do not pay money to use the software and do not install it on you computer. That is why we have the open source movement. People are fed up with these “use licenses” and are pursuing other avenues.
Well you left a little item out. Under your analogy you have to agree to all the terms before you buy/rent the car.
Don’t like the terms? Too bad because you already agreed to them and you can’t return because you put the key in the ignition.
Microsoft has had so-so luck enforcing their EULA. It won’t go any better for AutoDesk.
Is the agreement Constitutional? Can a retailer tell you what you can do with something you purchased something? In any other industry NO WAY! This guy trying to sell the software, not alter anything.