Scrap merchants yards are usually empty when the price it at its best they stock pile it until they can get the best price
For thinner materials you could go down to a breaker's and see what they're about to put in the crusher and make a silly offer to take some of it off their hands.
£120 to £140 per tonne ish
Oh & minus about £5 per tyre if you dont take them away.
all places that take cars to scrap have to have facilites now to remove all fluids from the vehiclesdont forget to take the battery off drain the tank and punch a hole in the tank and some insist on the oils and water being draind as well (engine gearbox and shocks!!!)
phone first as some places you can get away with alsorts