I always wondered about it too. As a little kid, I was a huge fan of this show, but my dad ruined it for me, by talking about how unrealistic the stunts were ("those guys would be dead or severly injured if they really did that, Champ...")
apparently they went through 309 Dodge Chargers during the making of the show (see also, mythbusters covered this (Myth 1,
here)), but it got to cost prohibitive. From wiki: "
Warner Bros. purchased several Chargers for stunts, as they generally destroyed at least one or two cars per episode. By the end of the show's sixth season, the Chargers were becoming harder to find, and more expensive. In addition, the television series Knight Rider began to rival the General Lee's stunts. As such, the producers used 1:8 scale miniatures, filmed by Jack Sessums' crew, or recycled stock jump footage ? the latter being a practice that had been in place to an extent since the second season, and had increased as the seasons passed."
Jalen Rose
bought one of 4 remaining original General Lees from the show, had the Confederate Flag painted over, changed the number to his jersey # at Michigan (05), and auctioned it off with the proceeds going to benefit the school he started in Detroit, all of which was pretty awesome, when you think about it. Take that, racists.