The club I belong to get quite a few requests for cars to be used in filming.
What I've noticed over the years is the fee being offered gets lower and lower. Latest one is for car plus driver for what they say will only be a couple of hours, and are offering 100 quid.
Now the agreed daily rate for an extra is 85 quid. Driving is a skill so adds 25 quid. Plus probably travel expenses.
Most of these sort of productions are period, so expect a car to be in the condition you'd expect then - ie very good. How much would anyone here expect to pay to hire a car for a day?