Heres a great option, $159:
http://www.thuleracks.com/product.asp?dept_id=8&sku=963
but you may need the extension to clear the width of the tire:
go to the spare parts breakdown and look at part #B, they have an optional one thats longer but I don't see it on the site
http://www.thuleracks.com/product_sp...t_id=8&sku=963