keep in mind 5k is a good amount for a 380. The thing I think it would come down to is how bad you want a newer car. When I get annoyed by the BMW I want to sell it so bad, but then when it's running right and I rag on it and the car flys I love it again.
Remeber your never going to get your money back out of a car and if you do you've done damn well in my books.
I personally would keep the 126 because I dont like the C very much being a fat kid.
Do what you think is best