My bias it this:
On a new car, stuff happens- if a car is modded and a defect totally unrelated to the mod occurs, BMW will likely deny any driveline claim due to the mods. This is their policy once the technician says "modified".
I'd give it 10-20k to shake out, then take the plunge.
I do not believe most owners can afford to be protected by Moss magnussen... Mike, with all due respect, your interpretation of 'voiding of warranty' and the practical aspects of how this will be enforced with BMW is not 'misinformation'. Operating a motor at higher outputs CAN adversely affect every other component in the driveline- rods, crank, transmission, etc. To think a 'chip' can only result in a 'blown turbo' is quite simplistic. Practically speaking many owners are stuck with the choice to litigate with BMWNA over a $20k repair where the cost of the lawsuit will be over $50k (I'm not saying with diesels, but just mods in general). The arguments you cite may be correct, but you will not be able to have an arbiter decide if your position is correct until you've spent way more that the repair on discovery, legal fees, arbitration, etc, etc.
now, if you don't care and are willing to pay your own way, I strongly believe that the best 'chip' is actually reprogramming the DME and not the piggy back stuff- remap it and be done with it.
I did it on my TT at 24k and couldn't have been happier.
PS No chip is 'undetectable'. You can clear the the 'codes' but the DME retains operating range data- if an engine blows up, BMW may send the DME back east to do a forensic exam....they look for this stuff. Burger and others sure do dance around about this, but you will find they only speak of 'clearing codes' and not the op data.
PPS Bottom line? Only do it if you are willing to pay to play...on the unlikely case you DO have an issue. Unlikely but possible.
Keep it as simple as possible...but no simpler.
Last edited by ard; 09-26-2011 at 01:08 AM.