Thanks for a great trip report! 18 summers ago a pal and I rented a car in Budapest for two weeks with hopes of driving into Transylvania. We noodled around rural eastern Hungary, having similar seat of the pants experiences (though instead of attitude-driven black BMWs we experienced the tension between the little 25 kpm blue trucks and the drivers on a cross-Hungary rally race. Friends living close to the Romanian border did their best to change out minds: "they will see the Hungarian plates and slash your tires. The Roma will steal you blind. There is a cholera outbreak in the Danube delta...." I chickened out, alas. Your trip sounds a little like what I would have expected to encounter (except for 2008 prices) -- a little hairy but interesting.

My grandmother was from Sighisoara -- sounds like there's no there there, though aren't there plans to build a Dracula theme park? Sure would like to see the painted monasteries, though.