I know we have hashed through a few of these before, but would like to hear some stories of cars you went to look at, didn't buy and now regret for whatever reason.   I know there are hundreds.  Can't be a car you just heard about, or saw for sale in a magazine.   Must be one you actually went to see, and hopefully drove, if it was drivable.
I just saw this on ebay:   
burned out 190SL 
I am shocked that a burned out example is over $10k and reserve is still not met.   Can't be much usable there.
ANYWAY.... reminded me of the 1960 190SL I went to look at in about 1973.   It was a very nice driver.  Came with a clapped out, but running parts car.   Could have bought the pair for $1,200,  but passed.   I thought (and still do) it was just too underpowered.