Can't drive my 2008 4.8i smoothly

[gazza-the-hut]

I find my 4.8i (2008) very difficult to drive smoothly. There are two problems:

1) However smoothly I press the gas pedal the car lurches forward unevenly. The only take-off that is reasonably smooth is if I floor the gas pedal which is fun but inappropriate most of the time.

2) When slowing to a halt using the brakes, the car slows down smoothly until it is almost stationary then there is a significant lurch as something in the transmission engages or disengages. It's as if there is a really heavy weight somewhere in the car that is moving forward and hits a bulkward or something.

I'd like to know whether these are normal for this model and whether anything can be done to eliminate these problems.