after being on here for the last close on 6 years ,i have never been short of a free nights parking .as for tesco ,if you ask the manager at the store you should be able to stay overnight ,ok some may not let you, also asda have a policy of letting you stay overnight on there car parks ,it all depends on wether they own the carpark or not ,some do some dont . if i am not mistaken i do belive the asda at merther tydfill allows a overnight stay never used it personaly ,but have seen wagons parked up curtains closed on a night . unfortunately i am without a van at the moment ,but we will still stay overnight in the car at times so the wilding is not over yet although not quite as comfy as the van the car will serve ok