I've owned a few of my dream cars, and most times the letdown overpowered the dream and I ended up letting them go. What do they say about "never meet your hero"? Same thing for dream cars.
The most notable:
C3 Corvette - the more I drove it, the more I questioned my own sanity in lusting after it in the first place. Was this seriously a production car from a major manufacture? I'd been in kit cars that were faster and had better build quality and body integrity. This was a very short dream, gave this up really quick.
C4 Corvette- It was actually pretty nice, light years better than the C3, but the horrible ingress/egress was a lot to deal with in regular life. And it nickeled and dimed me to death, even though it hardly had any miles on it...tie rods, u-joints, wheel bearings, brakes, fuel pumps, EGR issues..... Practically the only part I did NOT an issue with was the dreaded Opti-spark, which is the part I figured would give me the most indigestion. Traded it in for a new Mazda 3 which I enjoyed 10x more than I ever enjoyed the Vette(s). My days of dreaming of Vette's pretty much ended.
Rx7 Turbo II - This car almost fully lived up to the dream, but after just a few weeks the harsh ride became corporal punishment worthy of a death row inmate. It seriously felt like the suspension was made of concrete. Replaced the front and rear springs and shocks/struts for a non-turbo Rx7 and some softer tires. Turned it into a very liveable car which I enjoyed for several years but the short turbocharged Wankel lifespan reared its ugly head at a time where I wasnt able to sink the funds into rebuilding it, so away it went. But it sure was fun while it lasted.
Honestly the car I'm driving now, a shiny red lowly Fiat 124 Spider is as close as to a dream car I can think of right now. Its a Fiat engine, but the rest of the car is pretty much Miata and with the ECU tuned and aftermarket exhaust, the engine sounds magical, it goes like snot and plows through corners like they arent even there, and pulls 37 mpg while doing it. This car never, ever fails to put a smile on my face. I'd like to buy about a dozen of them, wrap them in bubble wrap and stick them out back in the barn to have a lifetime supply but the wife would never go for it. Anyway there's mice in there, otherwise I'd do it. I stumbled onto this dream on a whim and I'm glad I did.
At this point my only real dream car would be a red and black '57 Chevy convertible, but since I havent actually driven one I would have to refer back to paragraph 1.