So, This is the 1st truck I've ever had with a topper on it. I live in Michigan, and its starting to snow pretty good. Now, my back window and mirrors have defroster on them, but they do little good in trying to see out the review mirror when the back window on my topper is totally covered in snow. Is there an after market defroster wires, or a chemical that can be wiped on? What do you guys do? Thanks.