Wow, this is going out of topic so far...
Well, no perfect world and no perfect game. I believe GPx become even better if Geoff want to share _source_ codes, not compiled codes to game engine developer.
Back to topic. All questions are answered. I just give a suggestion, if car setups during wet conditions doesn't satisfy your soul, you can use Tyre Grip Against Surface Modifier in GP4 Tweaker to add some tyre grip so you won't slipped all the way during races. This is cheating though, so use it as own pleasure. Adjust the value below 150% are sufficient on most cases. Higher than that, then you let your AI opponents get "fantastic" lap time ever.
For steering help, sometimes it is still necessary when using keyboard. For wheel controllers, set to 0% is sufficient through control setting menu. Steering Help disabler in GP4 Tweaker completely bypass steering helper handler on the game, especially using keyboard or other switched controllers. For analog controllers, disable it just affect a little or none.
For Mike, there are some flagged codes defined in each "spot area" in track data files. These flagged areas are acts and coded just like a trigger. Unfortunately codes for these kind of flags is still unknown by tool authors. These flags used for many things, such as detect if your car still in-track or out-track, detect if your car passing a speed trap area so the game can decide if black flag should be triggered or not, detect if your car in a pitentry-pitlane-pitstop area and decrease car speed accordingly, etc, etc... I wonder why these kind of flagged codes still undiscovered since the first Track Editor utility for GP2.
Gr88ts,
Madman