Pulling wire through back of dash/bottom windshield

I don't want to go through mounting my external GPS antenna again because it needs the cradle/stand to connect it.
 
I'm going to place it on the dash in the center since the new software update has dramatically improved the tracking ability. 
 
Anyway, I just need to run the power wire behind the dash and under it.  Has anybody ran any power wires behind the dash where the dash meets the lower part of the windshield in the center where the pop cap is for the bolt? 
 
I thought I could just fishline it up from below the dash, but I don't know if there is a gap there or if something is blocking it where I wouldn't be able to fish it through.  There is enough space it looks like for the power connector to be brought up through the crack.