I have seen people change companies around on an unsupported reimbursement. The trick was actually data. In the case I'm thinking of it was cell phone records. While company policy was not to reimburse for cell phone use and cell phones were provided by the company only at a certain high level, I saw this get changed by somone who took the call list from his cell phone bill for 3 months, highlighted all the work related calls (nearly all of them) and showed them to his boss. He got reimbursement and the company picked up his cell phone policy.
I'd offer that similar might be possible here - have your friend track his mileage each day. On days with a pickup, note the event. After a few weeks, tally up the total mileage per week or month and the additional mileage that was added as a result of running errands. Figure out added costs using this as a percentage, and make sure you are comprehensive, presumably he's racking up:
- gas - average gas price * mpg * miles traveled for errands
- wear and tear on the vehicle - public sites will offer depreciation on vehicles, + cost of maintenance * the % of mileage for work vs. total mileage.
- a % of his car insurance. - insurance per month * miles for work/total miles
Find a figure and ask for reimbursement.
It's also a good point of reference... the $ involved for something like this can have little to no relation to the annoyance factor. Finding a dollar amount may result in either your friend having a very good case for why he should get some decent compensation, or he'll realize that it seriously isn't worth the battle over such a small amount of money - either way, the perspective helps.
Granted, I can see that the more value you provide to the company, the easier it will be to get a friendly ear for the cause. So a minor caveat would be - as a dispensible employee, anything you can do to become more indispensible is a worthwhile effort...