Any cautions on buying an RV with a lien on it, please ?

We bought one that way. But the bank was a major bank, and all of the paperwork was at some place across the country. We basically had to go on faith. I mean, we had the vehicle, and we had the seller sign a written sales agreement. But the bank doesn't sign anything useful, so we were at their mercy. Furthermore, they don't send the released title to the buyer, they send it to the seller. So we had to depend not only on the bank but the seller to get the title to us.