Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: IB+ Gold, TK E+, Hyatt Globalist, Marriott LTP, IHG Diamond
Posts: 14,182
IB+ has gotten rid of all of its car rental partners except Avis / Budget to come in line with the global IAG / Avis deal.
AFAIK you don't have to live in Spain, but you can only rent there.
You should also note that you have to pay a bunch of additional costs - airport surcharge, insurance, etc. - so unless you have a credit card that offers car insurance, you won't save very much by wasting a large number of Avios...