First of all, make sure to go the counter alone. If you have 5 kids with you they'll know your desperate. If you're a Costco member, try costco travel. I rented a minivan for 20$ a day through Costco. They don't take your CC so you don't have to use your reservation if you find a cheaper one. Also try a priceline bid. And as always, don't prepay fuel. And look around the whole van before driving off. Good luck!