I'm sure that somewhere has crazy rules but the general idea of a secured loan is the lender can easily take your security if you don't pay the debt. If not for that it isn't secured, is it?

Car loans are secured on a car. If you want to just borrow money with no security you can get a (likely far more expensive) unsecured loan if the bank judges this to be a good risk, or take an overdraft on a current account or use a credit card, all unsecured debt.

Collaterals don't require ownership by bank where I live. Loaned cars are owned by their loaners (but leased cars aren't, although they may transfer ownership to the leaser after a period of time, depending on the terms of the lease). Not sure how these things work in the UK, though.