Does your company require your employees to use their personal insurance coverage as first line of coverage in the event of a loss for rental cars? If not, what are your procedures? We thought it would be covered by a credit card that advertises coverage on auto rentals, but have now discovered they pay only what is not covered by other available policies - employee's policy and the company's policy.Thank you.

I doubt this is something you can require as a matter of policy.  It will be determined by the laws of the state in which the accident occurs.  Your liability policy probably can, if it does not, include employee drivers.  I'm not an attorney but I suspect that as a civil matter, the other party can sue whoever they want.  Do you think you can sue your employee to recover after your insurance company settles?  I expect that wouldn't work well and probably nobody would ever want to drive for your company again.