Ok then.
Open up the door and look behind the petal, do you see this black knob down there? If so, push hard on it and see if it CLICKS back, it should then pop back out. Yours is likely either broken or gone. Buy a new one! You can get it from Phil @ Fastlane, just be sure he looks under Acceleration Control (it's not under transmission in the Mercedes computer, they messed up).

It's the black circular thing below and to the right of the white screw, and it's directly behind the gas petal when floored.



Here is a closer look:



Do you see this on your car??

(BTW, when they put in a new transmission, I wouldn't think they put in a new kickdown switch if it's operating properly...)

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)