I had a twin tank setup in my hiace installed. Used ex optus/telstra tanks, as they are removed when the vans are sold. worked out really cheap for the tanks and brackets, which still had 6 years left on the stamp. I would say there is a good chance they would fit under the 32 with the spare removed, and they hold 130litres, enough for 700km in the old van. If your in sydneym try talking to broady automotive about the tanks, as they have heaps of them, just dont bother trying to get them to hit the setup, there not really interested in anything hiperformance.