see my post below about a6 with a GIAC flash
you can flash new software on the engine for just $250
it really picks up the car and for that price you can't beat it... it's the best mod for the money now... GIAC just released this flash @ that price last week
the best intake for our cars is the BMC CDA 85-150... you need to customize it a little bit, but it is the only filter on the market that provided cooler temps than stock air box, and 10% higher airflow. if you don't have the dough for it, a k&n panel air filter (goes in your stock airbox) will be a good little mod to start.
then you have no choice but to go custom on the exhaust becuase the only real kit i know if is from Supersprint and it costs well over $1000; you can have a nice custom setup welded for < $500
koni or bilstein shocks are the best replacements coupled with h&r springs, vogtland springs, or eibach springs (thats what everyone here uses) ~ and if you really got the dough then get coilovers (bilstein, H&R)
then theres sway bars, the hsport kit is the best hands down, costs $400.
then another mod, and more so maintenance that will come in your A6's lifetime, is control arms/tie rods. Febi makes the best kit (about $500) and it really helps the steering response and tightens it up.
on the interior, you can get all weather floormats for about $100... they look really nice imo. some people upgrade the steering wheels to sport versions, s4 steering wheels, or have even done RS6 steering wheels with paddle shifters.
that just leaves exterior mods. there really are no body kits that anyone favors too much... most are pretty ugly and. the best mods seem to be oem+ mods... like getting door blades from an S6 or Allroad. Lotsa people also get the RS6 trunk spoiler. talking about the RS6, it has pretty much the nicest bumper anyones ever made for the A6. there are companies that make replicas of the bumper but they're hard to get especially for a 2.8 (pre-facelift narrow body) ~ the only other decent kit is made by Rieger, and i personally am not a fan (and only know 1 person on this board that has it)
so that sums up the best of the best.
audio, tint, and wheels are all on you...
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