Saw this on PH and I've had this problem. I replaced coils, plugs and injectors and still have it.

Drivetrain software updates done (2005 DB9: Symptom: With 'Drive' engaged, foot on brake and car stopped (like while stuck in traffic) there is a periodic and fairly frequent shudder that I feel, much like a rough idle. But there's also a bit of noise that accompanies it that seems to come from somewhere below the car, possibly in the area of the torque tube or driveshaft. Shifting to 'Neutral' alleviates the problem leading me to believe it's not an engine misfire or idle problem. I believe the symptoms are the same while stopped with 'Reverse' engaged.)

 

Did you do the misfire correction learn after replacing the coils?

After I had my coils replaced I still had misfire issues. Turned out that one of the new coils was flaky.

 

I did and it still exists. Might be a trip to the dealer to see what cylinder(s) are misfiring.

 

You can find out the misfire if you have an obdii reader that can read the AM codes, that is how I found my issue

 

Did you ever get the problem solved? My 05 db9 is exhibiting the same symptoms. Thanks!

 

if its not happening in neutral its likely something to do with the transmission

 

Search clutch learn procedure if you've never done this. I'm assuming you have a paddle shift car.

 

OP has a DB9 with a ZF 6-speed auto. Yes it has paddles but it's not related to what you think as far as a clutch learn.

 

There is a learn procedure for auto DB9's, but that is for better shifting.

Get a good code reader, first time I had a shutter I did the misfire correction and the shutter was gone.