ruderacer wrote:I wonder what vehicle they used as a platform for the Mach 5, maybe a Corvette or Viper?
Depends on the budget. I remember the first "Fast and the Furious" movie used the most stripped version of every car that was available except for the Supra Twin Turbo. The Eclipse featured was basic, no AWD or turbo. The Volkswagen Jetta was a basic 2.0L model (no turbo or VR6 engine). The only things they did were to gussy them up with stickers, wheels, and shiny chrome-ish parts. They later sold them on Ebay, and made insane prices, probably because the dashboards were signed by the cast and for collector's value.
I think nowadays, they're just as likely to either use CGI, or use effects that make cars look fast, without necessarily making the cars incredibly fast themselves. Of course, maybe I'm just jaded.