I own 3 cars, all of them projects, and none of them with any desire to ever sell again. These cars will be with me and within my family until the day I die, and then passed on to my children if I have any.
Of the three, two are frankensteins.
'99 Porsche Boxster 986 with 996 3.8 M96
'85 Toyota Corolla AE86 with Honda S2000 F20C
It's also worth noting that, with all the money dumped into these two cars, I could have gotten myself a really nice 996TT or 997, but instead I have a 20 year old Boxster that's probably slower than both. The engine swap for the 986 cost twice as much (and counting) as the Boxster itself, and the S2000 swap into the AE86 cost 8x (and counting) what the car is worth. Even if I were to sell them, I would never get any of my money back.
... but then again, why would I sell them? I love my cars.