been given a car, no log book. owner missing. what do i do with it?

[freezingmytitsoff]

i have a family member who used to live near me. about 3yrs ago he moved abraod. he left a car at one of his freinds houses who lived near me. the car has sat there for 3yrs, his friend contacted me and said the council was going to tow it if it wasn't moved so i got someone to pick it up and park it at there parents house.
now the problem is we have no keys and no logbook!
i have till jan 1st to move from where it is.
the family memeber who owns it is uncontactable, i have tried every possible way of finding him but can't.
it is worth about 2,000 and i could really do with the money.
i don't drive and know nothing about cars.
what the hell do i do?

well police said that as there were people saying they had seen him around london that they weren't worried.
i understand that the laws says i cant take it but its not possible for me or his mum to store it and there is no way i would let the council tow it away.
im just doing what i know he would want me to do.
he would be really annoyed if he knew his friend had told it was going to get towed and i hadn't done anything.
also my mum has said i can keep it at hers for a while so i won't sell it for now.