No, you don't have to remove the bumper. I installed mine without removing the bumper. I also used Rennline template to cut the bumper.

Here are couple pics of my turbo.

 

One comment on the bumper removal having just done it this weekend for radiator grills. Without a lift is possible, but you will need to get the nose of the car off the ground at least a few extra inches, blocks, jack, jack stands, whatever, to put it back on. I could not get the underside screws to line up with better visibility from below.

 

I have the black vent smile on mine is that green one a rs? IMO i like that its more smooth and clean looking. Do they sell that vent?

 

I purchased the rennline kit. Worked well but make sure your jigsaw blade is thin, other wise it will catch on the template. It was scary cutting into the plastic but not difficult to do. Much much cheaper than buying the gt3 rs bumper and lights etc... pm me for pics

 

Pics please..wondering if turbo bumper guts are different than non tt? Did u need to remove bumper. Non turbo guys say remove bumper.?????

 

I ended up taking the front bumper off but I also removed the lower air dams and replaced with wire mesh as well.

 

What kind of mesh did u use? And where did u get it from?
U willing to sell the templet?
Can u send some pics?

 

I purchased aluminum mesh (sprayed with matte gray paint) in a roll from hardware store and hand formed and cut it to fit. Then anchored it with some screws to the old plastic vent pieces. The center vent I cutout the plastic with a jig-saw, some areas need to be cleaned up on the bottom. I'll fix it this summer. If I still have the C4S that is. Considering selling it since I don't drive it as much as I'd like to and need to buy some other toys

 

Templet for sale??

 

Sent you a PM, but yes.

 

Here's a video by Rennline themselves. While I like the gt3 smile and the idea of saving money on the mod, I am scared of cutting through the bumper.