Unconventional salesmanship doesn't necessarily relate to a rip off.
I've often been given more for my used car than what I paid for it
originally! But I bought the new car anyway. lol

No you didn't get more for your car than it was worth. What you got was a
discount on the MSRP of the new car, part or all of which was represented as
being for your trade in. A very common practice--often you can get the same
price and still keep your used car. You would have gotten a better deal not
including the trade-in during the negotiation, then when you have gotten your
best price from the dealer you offer the car for its wholesale value. Or make a
little more by selling it yourself.

Regards,

John