I did the FDM this weekend with no hangups. I put together my own parts from RMEuropean (switch & coolant), AutoZone (t-stat) and Walmart (water &
surfactant additive).
Here's what I used:
After driving around for a day or so, the most noticeable change is throttle response. The engine revs up much quicker when down shifting. This makes rev-matching when heel-toe-ing much easier and smoother.