Folding solar panel design.  While parked they unfold to collect energy and provide shade for the interior.  Once batteries are charged they will run an active cooler (A/C or vent fan) to cool the interior.  Will have an auxiliary mode to position panels for maximize energy collection.  Perhaps once converted to hydrogen fuel cell this would charge on board batteries enough for a handful of miles before using fuel.  H2O byproduct from fuel cell could be collected in small amounts and with regenerative braking and solar cells could be converted back to H2 through electrolysis.