Drilled a few holes in our previous TT's battery case bottom after reading about this a couple of years ago. Just got our new TT and went to do the same, lo and behold it was already done for me by the dealer it seems. Put a little smile on my face that morning.
Mike, Kim, and Pepper
(Min Pin security)
Current TT: 2012 Eagle Super Lite 308RETS
Current Hitch: Equal-i-zer 1400/14K
Current TV: 2010 Chevy 2500HD, CC, LB, Duramax/Allison