Hey mate, it happened to me in 1989. I bought a baby blue 72 sedan from my cuz that was all original for $700.00 then I traded it for a 1980 toyota starlet. I ended getting back my sedan in 1993 from a neihbor. I didn't even know it was the one I had because it was painted dark blue, with fiberglass doors,front and trunk. It also had roll bars inside with only the front seats and a rx-7 rear end with disk brakes. They swapped the original A12 for a A15 with all the goodies. It was running 12's in a qtr mile with NOS. But when I got it, I put it street legal. I had to sell it because My ex was pregnat and I needed a family car :( Dam I miss that car !!!

I regret letting go of any of my cars. I spend way to much time and knuckle skin on them. I tend not to buy one unless I really desire the darn machine. I remember on one occasion I bought back a particulary nice expamle of a 78 B210 that I had completely restored - dash pad - seals - engine - brakes - the works. I was very happy to get my baby back and on the way home late at night in the backwoods of Washington cruising about 75 the oil sending unit line snapped and bled all of the oil out in a matter of a few moments. By the time I realized it my engine had seized. Not a good night.

The motor and trans that are in my coupe were in my sedan when I sold it to my buddy in '89. he gave me the car back in '05.
Does that count?