Santa Fe 2010 mirror heater manual switch

We are looking at the 2010 Santa Fe and may very well buy it. One little thing I don't like is that the outside mirror heaters are controlled by a thermostat somewhere in the car's electric system. Our climate here is such that there is often condensation and raindrops on the mirrors. I would like, if we get the car, to bypass this automatic switching and have a manual switch that will energize the heaters for 10 to 15 minutes.

Any suggestions?

Thanks!

I wanted to do this as well, but even looking at the Electrical Manual I do not see a way to do it.

TS