My post was already running long so I left it to the one example of materials used to point out why a Cessna shouldn't cost more than a Torus. Aside from avionics there is little change between a 2011 C-172 and a 1960 C-172. The same can not be said for the car. Every single part of an airplane cost ten fold that of it's non-aviation counterpart and I do blame lawyers. Litigation is why a $10 vacuum pump costs $300. Maybe its Americans propensity to sue whenever something bad happens, of maybe it's a shifting from wanting to work to get ahead to wanting to get it easy. Whatever it is it manifests it's self in the courtroom and I lump it all together and blame the lawyers.
Point remains, theres no good reason for a new C-172 to cost one penny more than a new Ford Torus.