Long time reader, first time poster...
Since it came premodded, paying 20k for it didn't seem like a bad idea at all. So far, we've noticed the air box, K&N air filter, the intake (at least until I found out about the year, thats stock, I guess), headers (can't really tell the make), cutout, some suspension work (BMR), and Torq Classics(17x285 front, 17x315 rear).
Also have gone to a dyno day and it checked out at 318 hp and 325 ft/lbs. of torque. Felt slightly disappointed in the numbers but then I guess thats probably the A4's fault.
Probably droned on long enough for an intro but thats that. And again wonderful site, folks.
.......and I think your numbers should be higher than that too with all those mods.....If it has'nt been tuned I would definetly check into having it done, especially having headers and everything. 
