The NRMA and other pro-car lobby groups are household brand names that rely on automatic year-in year-out renewal of memberships for income. How hard would it be to nail their colours to the planet-killers mast with a few telegenic demo's, some letter writing, & one of two celebrity broadsides (first problem: find a celebrity with a spine). If BP can spend millions on new ads claiming to be progressive on global warming, it must hurt NRMA's brand to be tarred as malignant fossil fools.

If thats too moderate for you, maybe activist cyclists could declare all cars with NRMA membership stickers fair game - it is possible to dent two panels in one pass with end of your handlebar, with a little practice.

I've often wondered if it'd be called criminal vandalism to make up and plant bumper stickers, "doing my bit for global warming!"

I suppose if it isn't under law, they'd quickly change the law to make it so, a bit like how in Luddite days they changed the law to give you a life sentence for destroying a weaving loom...