Oh you can.
So if said person gets £350 a month, but they have a car which is worth £10k, but due to doing 10-15k business mileage could lower the resale value of the car over a 2 year period, then the extra cost in tyres, brakes, extra servicing, and so on... It is easy to lose money on it.
My basic is just under the 40% tax limit, but any extra screws me into the 40% rate. Which is why a car allowance is a bad move for me.
Yes, but technically with bonus and commission I'm bumped into 40% already.