I remember riding into Barcelona from some small town on the coast about ten miles north and seeing a car on it's roof, still smoldering on the motorway (nobody inside thank god). If that happened in Britain the motorway would have been closed off for at least a day while everything was sorted but cars were just swerving left and right round the wreckage.
In Barcelona itself remember seeing loads of cars parked by the side of roads in pairs, occupants examing dents and insurance details. Being on any of the motorways leading into or out of the city in rush hour traffic was like being in the final attack sequence on the Death Star. Inside the city itself wasn't too bad.
Navigation inside Barcelona should in theory be a piece of piss because all the roads are laid out grid like with the occasional diagonal, but in true town planning genius as soon as you get close to where you are heading you hit a one way system and get dragged off in some random direction (probably just me, I've got a rare talent for getting lost, or going round in circles for hours in largish cities).
Always found Spanish driving OK out of town, especially in more rural areas. Left a tankbag at a petrol station once, rode twenty five miles before realising when pulled over at the side of the road for a fag break. Expected at best a fifty mile detour to pick the bag up, was amazed when a car pulled up next to me and driver got out and handed me the tankbag. He had been chasing me for over half an hour when he saw me drive off at the garage.He even refused to take any money for his kindness.