Just wondering if anyone with an 07-08 base TL has done the conversion...I see a lot of 04-06 with type s rear lip but no 07-08. Wanted to know how much to cut and if I can leave the circled part.

 

mmade22 did a great write up on this already...
https://acurazine.com/forums/3g-tl-2004-2008-93/e-121-diy-installing-type-s-aspec-rear-lip-base-tl-bumper-709992/

 

you have to cut just around the exhaust a little bit to make it fit as the openings on the exhaust is larger on the TL-S versus the base TL.

 

the lip covers that part.

 

I did it. When you take of the bumper, you will be able to unscrew the grill inside that cirlce you are referring too. Buy the TYpe-s rear bumper mesh ($6) and using the existing holes that are there mount the mesh behind you bumper. This is will give you a quick solution to the mesh grill part.

This will cover the whole you can see below

 

My thread should answer all questions on what needs to be done. Do you like cutting up your new rear bumper? Your gonna love this mod. Happy Dremilling....lol.

 

Your thread is excellent... but on a 07-08... you dont have to cut whole bumper.. just the exhuast tip a bit. Leaving the center piece helps you to mount a mesh or grill of your choice.