Ride past, turn around, go back on the footpath and confront him.
No raised voices or aggro but its the whole "cyclists don't pay rego, shouldn't be allowed on the roads" myth.
Point out that rego does not pay for the roads, and that cyclists don't cause sufficient damage to society to demand it.
"You don't pay for the roads."
Point out what does pay for the roads (GST and general revenue mostly) and point to the trike and all my clothes saying "Paid GST on all of this"
"You'll get yourself killed" and goes back to his vehicle.
"10,000Ks says otherwise".
Got back on the trike and continued. I didn't realise how scared I'd been until I had ridden around the corner and found my legs shaking at the next set of lights.
For more info on this sort of thing, check out the Crankbusters link in my sidebar.