I think it is too pricey to trade
The only way to get it is a Level 23 ticket or a Level 1000 ticket
And various amounts of luck or patience.
An alternative is to work out where the car is on your used car list and wait for it to turn up. (You need to find what game day you are on... well worth it though.
Another is to Borrow a friends Bentley... Good luck with that