What car do you regret not purchasing?

[PaulE]

A Series I E-Type Jaguar coupe in 1981 when I bought a brand new 1981 Mazda RX-7.

Any old Ferrari that was available for $5,000-$6,000 in the early 1970's that now sell for big bucks. But $5,000-$6,000 in the early 1970's was big bucks for me that I didn't have!

[Bald Eagle]

In the early '60's there was a real C Type Jaguar parked on the street in Cleveland with a "4 Sale" sign taped on it @ $3500.
In the late '60's there was a Vignalle Ferrari 250 Mexico @ $6000
Both were old, tired, non-competitive race cars, both achingly beautiful, both worth well over 1mm today.
In the mid-70's I passed on an original series Shelby GT 350 for $10k which I felt was over priced.
So, in 2014 I didn't let the 2000 Boxster slip away and I love it. Have put many more happy miles on it in 3+ years than I ever would have with any of the above dream cars, though I would have made lots of $$ on any of those.
Larry the Bald Eagle

[Larrymal2]

A real 1970 Chevelle SS LS6 4 speed back in 1996 for $10K. I didn't buy it because it was a faded gold color. I probably could of buffed it out and flipped it for $15k at the time.