Mum had her house broken into last weekend
They stole jewellery and both her and her husband's cars
They have since found both the cars and are keeping them for a week for fingerprints
I personally wouldn't want the cars back but I guess there is no choice in this
Can they demand an engineers report or something similar to check for mechanical damage?
From whom would they demand the engineers report ?
Presumably they stole the keys so any damage is likely to be from over-revving, clutch abuse or clattering the wheels/suspension.
Take the cars for a drive, if there seems anything wrong then get the local garage to give them a once over?
My car was stolen and recovered, after it was released by the police the insurance company sent it to a garage for inspection. It couldn't be released to me until it had all been checked over.
The only thing I was responsible for was reporting to the insurance company that the car was ready to be collected once the police had finished with it, otherwise I would be liable for the police storage charges.
Sorry to hear this but heads up te week for forensics will almost certainly involve a storage fee at some dodgy pound which your mum will end up paying as under the excess. Leaving it for forensics isn't mandatory so I would get the police to crack on and release vehicles soonest (a week for fingerprinting!) or go and collect. When my car got pinched advice from insurance broker was to go get the car as the storage was £20 per day and to be honest if you've just been burgled you don't need the aggro.
You may be lucky and no storage fee but check to avoid a nasty surprise. On the car front not likely to have been ragged as the bar stewards want to keep a low profile.