Probably not  something that Americans are thinking about right now but while you are having a big freeze down here in New Zealand we are having a heat wave.  Tar and small stones are death to our belt drives.  So far I have been stopped twice and managed to remove the stuck stones off pulleys and belt
The mess also builds up under the guards.  No real damage as yet but easily could be if we are not aware of where we are riding and when

Well what can we do about it? 'It's almost impossible to mount a mud flap to the front fender, or to add a thin piece of plastic or sheet metal to the top of the belt guard on the side toward the tire . so I guess it's just something we'll have to live with.

Hiko , if that's the case ,why not place a mud flap at the front of the rear fender long enough to carry the stones below the swingarm. The tip of a plastic fender off a dirt bike might be used ,for it's strength and slight flexibility and ease of reshaping .

I can remember as a kid riding my bicycle - we would seek out the bubbles in the road tar and pop them with our tires. I don't ever remember is being hot enough to come off the road and stick to your tires.  The Township Road Department used to spray used motor oil on the dirt roads to keep the dust down - those roads could get very slippery in the hot summer days, and when freshly applied you could get free undercoating on your car.

The roads up here in KY no longer get "tar" - they use a rubberized joint sealer and it does not turn liquid in the sun.....but it does get squishy and flexible when it is hot.  The "tar snakes" on the road can provide some interesting "alternate handling" issues when you are banked over in a corner and hit one.....my little Ninja likes to jump about 3" sideways until the tire gets off the tar snake and back onto the pavement.