Matt, do you know if the shop did any break-in on the pads? Most of the "warped" rotor feeling that so many people complain about on so many cars, is not warped rotors, but an uneven pad friction layer on the rotor. In order most pads to work properly, they need to be properly bedded. This bedding process deposits a friction layer from the pad to the rotor surface. If not done or not done properly, the friction layer on the rotor can be uneven, and it causes the "warped" rotor feeling. Find a nice open road and follow this pad bedding in procedure, and then see if the problem still exists: http://www.stoptech.com/tech_info/wp_bedinstock.shtml

John, thanks for your help. I actually did that procedure myself as the shop replaced the parts and handed the keys back without driving it. I immediately followed that procedure. Frustrated today, I did the bed-in procedure again thinking "To hell with it, if I ruin it, I'll just replace the parts again". I let the car cool all day then decided to check the tire pressures and that's when I discovered a big issue.

There was a 10psi difference between the right and left front tires. I keep a regular check on these things, so I can only attribute this to a few 90F days and 55F nights we had recently. I couldn't find any tire damage/puncture on the suspect tire but I'm going to keep a close watch. The 135i was giving me low tire warnings the other day as well. I really wish I could get the tire pressure feature turned on in my car by Steve! After adjusting all the pressures back to the appropriate settings the shudder is greatly diminished but still there. The rotors were pretty cheap for the X-drilled 12.8" diameter they are ($79/each) so maybe I just got what I paid for. I'll go with Zimmerman next time for sure.

Matt - see PM

I basically agreed with Johnand but gave the following advice

quote
"With disc brakes you also need to be careful you don't warp the discs (rotors in US speak). When the brakes are hot after driving - never put a hose with cold water on the discs to wash wheels, never drive through a car wash - never drive through deep water. Allow the brakes to cool first. People don't realise just how hot disc brakes get. You can actually cause micro cracking in the disc." unquote

Rotors can take the normal splashing from rain but excessive cooling can cause trouble.

Thanks for your help Glyn. The car was really driving sloppy the past 48 hours but it was definitely the tire pressure issue. You and John and Mike(?) Leskovar are truly the gurus here.

Well, I finally ordered my rear brake parts.
I've got Akebono EUR779 pads coming from
partsfactor.com a company off of Amazon that had the best price shipped
and the EBC slotted and dimpled rotors...
GD891's from Autopartwarehouse.com
I found a discount code after scouring for a while
READY4SUMMER
Saved me 10 bucks so the price was like 142 including tax.
Autopartsworld wanted like 70 for the Akebono's, and the other place was like 52 + shipping. 58.13.
If I'd seen the discount from Autopartsworld I might have bought from them, but then I had tax added so it would've been like 75-80 with the discount. OK, yeh, money IS tight and so am I.

Well...then again, I did cook garlic prawn and mushroom pasta last night with a botttle of Rombauer Chard...so it's just a matter of saving the denaro for other things...

I would prefer that they are NOT gold, but that doesn't seem to be an option. The
zinc will wear off quickly I imagine. And the look more closely match the drilled fronts.
Here's a pic on a pontiac. Anyone have pics of them on a MB?

here are the same rotors after 10k miles of use, not a close up pic , but you can still see the rotor.

if you want a close up pic , with no wheel on it, i'll be happy to go downstair at 10:00 am in the morning with a hangover, take my wheel off, borrow my sister's camera and take that pic. I guess that's nothing compare to the good info you supply here!

I have the same scraping noise and slight vibration with my cross drilled Brembo rotors. I contact Brembo and the representative told me they have had problems with the Brembo rotors and EBC pads. Two different reps suggested I change the pads. I plan to change them next month so I hope it resolves the problem.