[jackson1442]

Would be interesting if they offered a subscription service and/or loyalty tier that gives you "real" reservations. Call it "$BRAND Car Guarantee." That way, you know that the customers are committing to actually get their cars, and you can make a term of service that you don't miss N cars per T time (this would be displayed prominently - call it something friendly like "house rules").

Boom, everyone's happy. Your repeat customers are more likely to stay that way, and people will hear about this and _become_ repeat customers because that's what it incentivizes. You can keep prices cheap by overbooking your non-loyalty cars like you already do.