Tarragona and Barcelona were great places to visit. We drove to Tarragona easily enough, and parked with no problems. However, the courier rightly advised us that driving to Barcelona wasn't a good idea, and that we should instead take the train from Coma Ruga train station to Barcelona. It's worth noting that a car is needed (or taxi) to get from the campsite to Coma Ruga train station (which goes by a different name - St Vicente de Calders.)
The beaches are stunning and there was a pleasant, relaxed feel to the area. It caters to tourists without being too tasteless-ly touristy.
The nearest town, Roda de Bara, had a wonderful mediaeval night market one night, which we wouldn't have known about had we not driven into the town and seen a poster earlier that day, so it's worth keeping an eye out for local advertising.