One of my best friends family's has a shop that specializes in putting together cars that have been in accidents, stollen, etc... and selling. Most have R titles.
There are some things to keep in mind when buying a car like this:
1 - How bad was it actuallly damaged? A $5,000 car does not need to be hit very badly to get an R Title. While a brand new BMW might have had $40k worth of work done on it.
2 - Any car on a used car lot could have been in an accident...a very bad accident, still have a good title and not show up on any reports. My friend Vic had a 2001 Cherokee. It was hit to the tune of $21,000 worth of damage. Insurance gave him a check and he had it fixed on his own and traded it in an a new car. Clean title, no car fax data showed up when I ran it three weeks after someone else bought it.
3 - Do you know the person that did the work?
4 - Pay no more than 80% of the loan value for the car. If you pay the right price, an R title car can be a good buy.
5 - If you keep your cars a long time, then an R Title is a good way to go.
I setup my wife's g/f with a car from my friend's shop. 6,000 original miles. Two door Alero and it's an '03. Car was hit in the front hard. Since it was leased, they did not give it an R Title. THIS HAPPENS ALL THE TIME WITH LEASED CARS. Car still has original warrently on it. Car is fixed and sold for only $7,000.