Israel's tough, because the vast majority of the cost is in the mandatory insurance and taxes--not the actual rental fees. If you must rent from Avis, look for links from haaretz.com or elal.co.il for slightly lower rates than avis.com (and remember that avis.com may not fully indicate which insurance is actually mandatory). Hertz will sometimes knock off 10% for AAA members, but it can be tough to get it to work.