Not sure how much information is needed, but let’s say something comes up that requires substantial driving which the employee is willing to do with their personal car.
Beyond their wage what do you think is a reasonable approach to compensating them for the use of their car? Specifically due to depreciation, wear and tear.
If it makes a difference I’m interested in the theoretical approach rather than what I can get away with or something like that.
In canada you can issue a T2200 which is a declaration of exactly this type of usage. The form basically says yes you use your personal vehicle for work. This allows the employee to track mileage, repairs, maintenance and deduct that as a % from their taxes. So they will look at what % of the time is the car being used for work.
I am sure there is a similar form where you pay taxes. (this form is also used if there is a home office, or the person uses their cell phone for work)