A side note here which convinced my employer to get company cars.
Insurance usually is valid for private use only, the second you step into the car for work purposes you usually aren't covered. hence the title on most policy's = "Private motor vehicle insurance"
The bad thing for the employer (bonus for you) is that it becomes your place of work and in instances of accidents they may be accountable for losses there.
It is a bit of a gray area in insurance but worth noting if you do use your car for work purposes. Also a good argument to get a company car.