I investigated this a while back looking at the GS300. The auto up only functions because of the safety features built into the windows. If you apply pressure on them for X seconds they roll back down as it's assumed that something (or someone) was stuck in the window. The sunroof does the same thing. Now, as far as I know of (in my Gen3) the windows don't have this safety feature as you can't roll them auto up. The Gen 4+'s may have it, and make the switch swaps easy and legal. But I'm not sure.
So, technically, you can hack switches in to make them do this, however in doing so it's illegal because you're bypassing the safety mechanisms. (I believe)