I absolutely do not ever miss any car I sell.
There is a good reason all of my cars have been sold - to free up cash for 'necessary' things or trading up.
When they are sold for necessary things, it forces you to be creative about where to get your driving kicks. For instance, I would never have owned an RS had I not sold the 330 and needed £14k for a new kitchen!
French sh!tboxes weren't even on the radar
Glad I did though! If I want another BM, I'll get one when the time is right and get an E46 or E90 M3 depending on funds. Job done.