I have a 2008 TT and I upgraded my system today. Incase anyone is planning on doing this...it worked perfect...loud...clear...and easy! Did it in 3 hours!!!!

I bought a JL Audio CleanSweep DSP and JL 6450 6 channel amp. This could possibly work for any Audi with Bose. The speakers handled the new power without a problem and it sounds 10x better than b4. Highs and lows are great now! I took out Bose amp completely. Small plug on Bose amp is from radio. Connect those to the DSP. Other big plug is to the speakers. Most of the twisted wires go to speakers. My speakers in my car were either 2 or 4 ohm speakers.

Everything wired in paralell----
Ch1. Rear Right speakers and front right mid--HighPass
ch2. rear left speakers and front left mid--HighPass
ch3. Front right woofer--LowPass
ch4. front left woofer--LowPass
ch5. front tweeters and ceter speaker----3 wires all together.--HighPass
CH6. nothing.

For all of those with the stupid IPOD interfaces that do not show song names on radio....the Cleansweep DSP comes with a volume **** and aux input. Wired my IPOD to that with a headphone jack sticking out of my asstray and...bam..plug it in to my ipod. I could control the volume from it and see what song is playing. I can not emphasize what a drastic change this upgrade did to the way the system sounds. All for under $500 if you look on EBAY for the equipment. Then go buy some RCA cables and there you go. Use the amplifier in SUM mode so it takes 4 channels of input and outputs it to 6. No need to use splitters on RCA's. In the TT the wiring was very easy since the battery was in the trunk and as the amp. Battery had terminals on it already to connect the wire. Common gound is right next to amp. The DSP has a automatic EQ and clibrates itself when you load the calibration cd into your radio. Adjust the crssover and levels on the amp and u r set 2 go.