Only legit stuff, no questions to answer.
I see. Interesting. You keep on updating it? You automatically add a coupon as well if it's relevant? For example, if the app sees its more than 5 days, it applies a one day free coupon from whatever car rental company offers it?
How hard would it be for you to add an advanced mode for someone to enter his own codes if he's a legit member, or if he wants to try his luck at getting a better price.