An estimated mileage charge is required for every rental and any miles driven over 100 miles per day are charged per mile.*  The deposit and the per mile rate is charged according to your van model.
Santa Cruz & Mavericks: the $30/day deposit covers 100 miles per day, averaged over your trip. Excess miles are charged or unused miles are refunded at $0.30 cents per mile.
Big Sur (US) & Jeep Camper: the $33/day deposit covers 100 miles per day, averaged over your trip. Excess miles are charged or unused miles are refunded at $0.33 cents per mile.
Big Sur (Canada): the $45 CAD/day deposit covers 150 kilometers per day, averaged over your trip. Excess kilometers are charged or unused kilometers are refunded at $0.30 CAD per kilometer.
At drop off, if you have driven less than the amount covered by your deposit, you will be refunded at the corresponding mileage rate. At drop off, if you have driven more than the amount covered by the deposit, you will be charged for excess miles at the rate that corresponds with your vehicle model.
*Applies to bookings made on or after June 8, 2020 in the US and July 7, 2020 in Canada.