Its difficult to comment on all automakers and be accurate, but the answer is yes. Automakers are constantly looking at what the other guy is building and testing it. How do you make a american sedan drive like a bmw? Buy a BMW and test it on all kinds of machines. You can use the info to tune the suspension and do other things and make the car handle more like the other one. Plus, cars are not expensive for a company that does business in the billion. A few years back GM did a roaming test drive event, they called it the GM test drive on wheels, or something. Basically, several gm haulers would show up at a stadium on a saturday, and unload a ton of cars. They would set up small test courses and allow all kinds of people to drive the different cars. There were Gm vehicles, saabs, chevys, hummers, trucks, cadilacs. But there were also competitors vehicles. ford, dodges, and all kinds of other cars. The idea was that you could best test drive different cars on the same course back to back. GM bought all of those vehicles, and probably sold them afterward. But yes, companies buy cars all the time from competitors. Ford buying 10 chevy trucks does not hurt Ford and doesnt really help chevy that much, as both companies sell upwards of 600000 trucks a year.