So to confirm, is RMC track now a part of the official OpenRCT download, or still a special file you need to screw around with?
It's in the game now. As of a few weeks ago, back when I first tried it out, you had to be on the latest development build of the game. Don't know if they've updated with new release since then, but otherwise the dev build works great.
You can access the ride through your object/ride selection or mess around in the coaster track designer. There're actually two ride types that appear identical in the menu: one just uses the B&M track, the other with woodie track.* So when you build, it'll appear as one of those (but with the RMC trains).
But here's what you do: turn on the "arbitrary track types" cheat so you can access that dropdown menu (bottom of the ride's pop-up window). And select Hybrid Coaster track! So theoretically, you could actually build a typical woodie and "RMC it" (or wreckit
) with the click of a button!
*And depending on what type of RMC you select, you'll get either the woodie sound effect or B&M roar.