Those tap drills are a dream. I have gotten so used to them that it's nothing to use my ratcheting hammer drill with one of those bits. I have 1/4-20 and 10-32. The latter is a bit more delicate, I did break one when I was trying to tap through a clearance hole in the fiberglass. The bit contacted the fiberglass and going off angle snapped it. But the 1/4-20 has been indestructible after 100s of tapped holes. I usually don't even bother with cutting fluid any more.....
Here's you picture as promised! This is a tunnel vent that's designed for the standard splitter sitting on top of the tunnel that's integrated on the track day splitter:
As far as cutting holes in the fiberglass, this is similar to what Pete posted but is electric instead of pneumatic. Someone here recommend it. I have an angle grinder, a Dremel tool with various cutters, and a sawzall. But none hold a candle to this if there are any curves involved:
Harbor Freight
I also followed the initial recommendation and bought these too
[ame="http://www.amazon.com/Lenox-Tools-20427424T-Airsaw-5-Pack/dp/B0028W0V0M"]Amazon[/ame]
but I'm not sure if I'm going to need them. The blade that comes with the saw is nearly identical, same 24 tooth design.
Be sure to buy the warranty with the tool at harbor freight. I'm on my 2nd saw. The first one overheated the first time I used it and seized up. I thought I could fix it by opening up vent holes in the case and that didn't help. I bought a 2nd one with the warranty and waddaya know, it runs like a CHAMP.
I tried using one of the Lenox blades in my std size sawzall and it was way too much for the blade. First time the blade came out of the cut, it got bent like a pretzel before I could even react.
If I have a straight line to cut, I use my angle grinder with a 4.5" cutoff wheel. Regardless, the way to get a great looking edge is leave about 1mm of material, then file the rest bY hand. If you're relying on a power tool for your finished edge, you're setting yourself up for heartbreak.
A.J.