I use one of these two http://www.doyouspain.com/index_fullframe_2.html or http://www.rentalcars.com/?affiliateCode=google_brand&preflang=en&label=rentalcars.com-brand-QMBxf9tHoSbRGoWKQmhm3gS59135365143&ws=&gclid=CM-26OvH7cwCFUORGwod1xEKCw
Both pretty good but if you want excess insurance cover...