So here's what you do.
Submit your ACTUAL receipts for the rental car (along with those case decisions if you like) and ask for reimbursement. If the adjuster stands pat with $30 per day here are your options:
1 - Accept the money and get on with your life.
2 - Sue the driver and try to convince a judge that you are entitled to all of what you spent.
3 - Do nothing and get nothing.