nightmare time.. two ways the legit long winded loads of effort and probably wont get moved way.. or the other way.
the legit way is report to police and dvla IF they are on a public highway..
IF they have registration numbers and are taxed and insured they can stay there forever as long as they are not blocking the highway
if they are on the road but no tax/ reg no.s they and thier owners are still identifiable via the vin number but the police literally couldnt care less.
if the vehicles are on private land they can stay there forever..
if someone cant be bothered going down either of these routes they might choose the nuclear option and burn em to the ground. the same person in the past may have towed them to a scrap yard but as its now impossible to dispose of a car without the v5.. in theory this option no longer exists.
when i worked for tesco we literally had up to a dozen long term abandoned vehicles in our car parks.. iw as always amazed when someone turned up after 6 months and simply drove them away. we once had a low loader turn up at Prestwich in the middle of the night and take a car.