[ratgreen]

Maybe water sprayer over the condenser. I can't really think of anything else to improve the efficiency of the ac system.

change the blower motor resistor to a PWM motor controller (more electrically efficient and also most blower motor resistors sit in the stream of air vents to cool them, effectively warming your air slightly)

Insulation, inside and out.

Wrap the roof in white

Silver one way mirror tints on all windows and large sunstrip on windscreen

Cool the seats with in seat vents (basically cut out channels in seat foam and put fans in)


More expensive options are to then start going for dc compressors and powering it off solar panels on the roof / engine braking etc. The cost of which would be many times more than fuel savings.