Living in IL, I had to get an I-Pass, (similar to e-z pass or sunpass)
Being annoyed with a little white box either on the windshield or around the dashboard decided to due a slight modification. By keeping it in the glove compartment (the one for ppl with no navi) it worked with low speeds I cut my i-pass open in hope i can fit the board around the clock area (unsuccessful). Since one side of it broke during the process i ended up with one plastic cover in which i placed the circuit board. I'm pretty sure unopened i-pass and other transponders will fit in this spot.
Inside of the i-pass
Removed the housing around the clock in a (coupe 06) but that board does not fit in there, going to solder a cable to the board, at the end of what looks like reversed C in hope it will improve the signal, if the signal can be picked up just from the cable i will hide the I-pass and run a cable to the side pillar, otherwise it will be hidden behind the dome lights. Any input is welcome, thanks.
-- That did not quite work, what it seems to be the antenna of the transponder (reversed C) after being slightly scraped off multiple small holes were showing, so I gave up on the idea of soldering.
Procedure: for 05-07
1. Remove the (F) Cluster Lid Finisher Upper (Service Manual IP page 12) -- takes some force to get it out, pull it towards you (towards the back of the car)
2. Remove the (G) Cluster Lid Finisher Lower (Service Manual IP page 13) -- what i found that works best is starting at one side and proceeding towards the other with slight force the clips let go one by one
3. Removal of the clock along with the display -- might find it necessary if your transponder won't fit,
a) remove two screws on the center underneath the clock,
b) pull with slight force on the upper edges (one clip on each side) the display slides out at a angle
c) either set the display with the cable connected or remove the cable (if you remove it, you will need to reset the SRS otherwise the airbag will blink, the 7 times OFF to ON procedure for reset, with switching to off right after the airbag symbol turns off)
4. Right in the middle underneath the Cluster Lid Finisher Lower there will be a metal bar that holds the bracket for HU, that is where i applied some foam and fished a zip tie underneath it to secure the transponder
Applied some additional foam to the transponder on the edges, it might touch the dash
5. Secured the transponder and started putting everything together.
Tip for putting back together those two clusters, they suppose to be attached on the edges, while placing the bottom one first i was never able to make it "click" together with the upper one, which resulted in a gap on the corners, what i did was put them together and insert them as one piece.
Tests were successful, open road tolling and the toll booths work