Just run the vent out the bottom of the cowl. I use Tygon tubing to penetrate the FW with a 90 degree fitting to keep it close to the FW. On the down stream side of the 90 I use either brass or some high pressure 1/8 th" ID air tube and clip it to the FW with nylon molded LG straps (Goldberg etc.). This keeps it awat from the hot muffler. Nothing more fun than a dead stick with a 20lb. + plane due to a melted and fused shut vent line, been there don't want to do that again.
Just use some common sense and remember that the gas exhaust is much hotter than glow. It will melt most anything plastic that touches it. This goes for hot exhaust gas leaks too, but thats a subject for a different thread.
Too bad I saw this thread this AM, I had my current Laser with a G-45 apart last night to do the annual Spring service, so the cowl was off and I could have taken some pic.'s.

Lou