Re: Thank you
I prefer the cash vs car model since they are both things you can easily imagine being lent.
If I lend you a tenner I expect £10 back a week (or whatever) later. It doesn't have to be the same tenner - wouldn't be much use if you couldn't spend it. Another tenner will do. Doesn't even have to be a tenner, two fivers work equally well. Money is fungible.
If I lend you my car then I expect MY car back. Another car is not acceptable, even if it is the same make, model, age, mileage etc. I expect the specific, individual car back. Cars are NOT fungible.