Tezzer199

I have a is200 99 auto the 2001 is300 have e shift where you can down shift and up shift in a sequential manner I was wondering if it’s possible to add to my is200 will I need a different transmission or can I wire somthing up? Wanting a easier way to down shift rather than using 3 2 L the pwr mode does not hold gears around corners and shifts too often