my seatbelts (all of them) work fine but they seem very lazy on their way up, before i bought it the car sat in the spanish summer heat about a year, could they have lost lubrication? in that case what should I lubricate them with, wd40, grease?. if not do i have to change the belt drums or springs or something.

I would like to get this sorted quickly. if anyone has expirienced the same i would appreciate any help.