I saw the Startech 3.8 XF earlier this year, and they wanted about £12k (for the full 3.8 conversion) to upgrade mine (0-60 in 6secs). I reckon that the SRT-6 is a much better bet than the 3.8. An alternative would be to get the AMG-SLK320Kompressor engine and transmissions etc.

I think the cost of the Startech 6.1 engine/trans alone would be way too expensive (especially for those whose native currency is Dollars).

If I win the jackpot lottery on Saturday, I would probably buy it.