I dont think its necessary to keep the first 2.
I think you should know by the time youve traded up to your 3rd Ferrari or even moved from Ferrari to Lamborghini/Maclaren.
Not me. I'm home with Ferrari. Lambos attract the wrong crowd and McLarens are too difficult to drive. A friend had a McLaren and said to put it in "launch mode" you had to do four things simultaneously, some for "at least three seconds but not more than four". LOL. He usually couldn't get it to work.