[Perfectlap]

was a brand spankin new engine? If so then the car was worth more than $20K
But you are now in that territory where further money invested will start to question whether you would have been better off buying a newer model.

I've seen this same situation replayed with many Miata owners I know.
They will get a Miata for a very good price and then put money back into so that its back to close to the real market demmand value they avoided paying in the first place.
Some wisely sell for something newer while others continue spending and spending an spending.
I guess the object of the game is to get back as much as you put in. Or as close as you can get to it.
Because afterall anything that can be resold is an investment.