I asked if I could have heated seats added to my car when it was built in late September, and was told the same - insufficient current from stator (alternator thingy).
I've also got a single after-nmarket sit-on seat heater which doesn't take as much current and that seems ok ie. voltage doesn't drop too far with it on (using the voltmeter on the dashboard). But it's not very pretty, and I find with my WW2 flying jacket and a few other suitable clothes I stay pretty toasty (so far). Not so good for passengers though who don't have the gear and don't believe what they should be wearing.
No passengers improves the shoulder room and power to weight ratio so is it a problem....???
