Okay is it better to cut a hole in the bottom of the trunk or fender well?

Well, you need air flow, I would suggest the very front

I cut mine on the fender wells as described in the directions that came with the kit. Renegade also suggests the fenders as well. The bottom will give you lift at higher speeds. Dont try to reengineer it, just do what is tried and tested.

This has been discussed a lot. Do some searches, as it is interesting reading.

Bottom line though; vent through fender wells, not the floor. Or through the hood - if done right that will give you the best downforce.

I agree, the fender wells are the only place. If you check the threads you'll see where someone used a pattern of holes instead of a big cutout and it looked great, I wish I had done it that way. Also if you get the radiator vertical and forward, there's plenty of room to mount a colapsable spare with the compressor & some tools inside. Also, if your thinking of a heater (which you might be in Ohio), I found an alternative to installing a heater core. I didn't want any joints in the cooling hoses betwee the engine and radiator (one piece all the way). So what can be done for heat is to attach a marine "bilge blower" to the inlet of each defroster box (one strip of self vulcanizing tape make a real tight fit). This is where the OEM hoses from the rockers came up and attached to. It's not as hot as a core as the radiator begins to heat up but once the front trunk area is up to temperature, you get all the heat in the cabin that you need. Only one issue I haven't solved yet is how to easily turn off the free flow of hot air into the cabin - right now I take the bulkhead seal on and off which keeps it simple since not much hot air free flows in anyway.
Something to think about.

Thanks guys I like the idea of small holes. Sounds like a great idea and a reason to break out the chassis punch. And a flaring die would make it dead sexy Yeah!