I just picked up my 09 G37xS (traded in an '06 M3 that had come off of mfg warranty and was starting to give me major problems). Since my G was manufactured in Oct 2009, I assume that the harsh 4-3 downshift flash already came "pre-loaded" on my G, which would explain the acceleration lag many of you are experiencing. To be honest, I spent an hour at the dealership trying to decide between the AWD sedan w/ Sport pkg and the 6mt coupe. I ultimately went w/ the sedan b/c I didn't want to fool around with having two sets of tires/wheels anymore. I almost went the 6mt coupe route b/c of the acceleration lag, but before making my decision I decided to test drive the sedan one more time, but this time using the manual shift paddles. As you can imagine, this made a HUGE difference and I no longer experienced the acceleration lag that I did while in full auto mode. I always thought that the clutchless manual modes were stupid, but this is one case where I will find myself using the shift paddles for a truly "practical" reason. Other than the new squeak coming from the windshield/dash contact area, I am super satisfied with my (liquid platinum) G. I replaced the OEM wheels/tires with the coupe-style wheels and lower profile and wider A/S tires. I just had 35% tint put on all the windows, and will have the clear bra, midnight grille, rear lip spoiler, and front chin spoiler put on next week. I'm psyched!

FWIW, previous four cars prior to the G37: 2002 325ci, 2005 G35 Coupe 6mt, 2006 GS430 (great car, TONS of squeaks/rattles though), and 2006 M3 6sp (hands down the best $50k car, so long as it's still under mfg warranty!!!).

 

Congrats on your new G. I can feel your pain, we owned an 02 745Li (out of warranty) and it was the biggest POS we've owned. I drove one when new and it was the finest driving automobile I've driven. I'll NEVER own an out of warranty beamer ever again.

 

My 09 S sedan built in Aug/09 but still have the 3-4 and down shift flare at stop sign. I took it to the dealer, first time they said car was running lean, re-calibrated air sensor. The down shift problem got worst; I took it in again, they look at it and say that how the car shift and there is nothing they can do! But when I drove home the down shift flare almost went away and is barely noticeable for two weeks now. My car does not have the hesitation or lag from a dead stop, in fact it would jumps real hard from stand still. I do not even have to floor it, just step on it real quick and the tire would start to loose traction and the traction control have to step in. I would say if you have the lagging problem then have the dealer look at it.

 

I pickup my G37Xs in beginning of December and I am having the throttle lag problem as well. I think the built date is Aug 2009 but will confirm

At first I thought I need to wait for the breakin period and let the car learn my driving habit. But after couple of times merging onto the highway at 20-30mph where the car wouldn't speed up. I thought I research the problem. This is a serious problem!!! Just like some, I almost got rear ended. It scare the crap out of me and had to turn around and go home to change my underwear..lol

My mpg kinda sucks (screen indicates 14mpg) and I dont have the breaking problem. So, I would assume they flash my ECU prior to delivery.

The car I have now, compare to when I first test drove a G37X (non sport) it is night and day. You touch the gas pedal and it goes on the demo car! So far its been disappointing along with keyless entry sometime not unlocking, and with the radio flipping to ipod after couple of seconds of starting the car. From what I read, this is a fruitless effort but I'll give the service dept a try.

 

Try putting the car into DS mode when you are getting onto the highway.

The radio is probably switching to IPOD because your battery was dead in the IPOD, and when you turned on the car it started up again. That causes it to switch to the IPOD as if you had just plugged it in. I know I have this happen when I don't drive my car for a day or two.

 

Thanks KLB for the IPOD insight. As for switching to DS mode when getting onto the highway. It just sucks we have to do that to mitigate the problem. Given the 2 evils, I'll take the gear changing problem.