The hype is certainly over in the mainstream classic car market, and I guess that is now flowing down to the 'modern' classics as well. Buying cars as an investment is a fairly new phenomenon, with the exception of the ultra rare Italian and German exotics, and there was never any expectation that it was here to last. There's a simple answer to why there are so many Vees (and older classics) for sale...they are overpriced! I'm sure that the top cars will hold up well, but there are some poorly restored classics, and cars with no provenance / high miles / many owners that have always only ever been driver cars and not of interest to the collectors. I guess we will see those go back to the levels they were at a few years back, which has to be good thing for enthusiasts.
Even with the 'gold plated' investment exotica owners there have been mumblings and some disquiet with recent statements around the world about phasing out internal combustion engines in the fairly near future. Investment is about desire and confidence in the commodity, and whist the desire is still there, it's been now stated that there is no future in the car as we know it in the long term, and that's bound to start to rattle confidence. Sometime!!