clearing windows

[L4MBOLUV3R]

ive recently done a bit of upgrading to the I.C.E in my car, which resulted in a last minute change to the amp postion and left me with a sizeable hole in my parcel shelf where the wire feed was meant to go. so as you can imagine its pretty strange seeing a random hole on the parcel shelf so i have been thinking of ways to fill it. i came up with a few ideas but one struck me today which i feel might work. now since its cold again all the windows in my car have started to mist and the back window is the hardest to clear! so i was wondering if...

i placed a fan under the hole in my parcel shelf would it clear my back window quicker or have no affect?

and if it would work how would i go about attaching it to the existing fan control system?

and what fan would i need/could use?

thanks in advance LL