Rainbow Road (aka RR) is Mario Kart: Double Dash!!'s sixteenth course, and Special Cup's fourth course.
3 Lap
0-1-1. For mid expert: 1'02"9 - 1'01"4 - 1'01"6 = 3'05"9
1 SHROOMER
This is a long, long track, so if you are sweating because you want to set a good PR for yourself, then it can be irritating the whole, long track (something like 3 minutes).
Anyway, just take the turbo boost and as you hit the rainbow, do the shroom. When it's running out, build up an SSMT R and release it. Do 2 more from those R's and take a tight slide at the first turn. The fire may be red, but don't make it blue.
Then you do another slide to the right.
Do the Mario at the zipper, create an R on the lower rainbow road and do the Mario on the next long zipper again. Do an R on the other rainbow road (as it saves about a few split seconds) and then do the spiral with the countless zippers; try to hit them all but 1 or 2 of them.
Then you should run out of 70mph, or 100 km/h, so you should start with an R again. Another R, then L , R and then L again, and take the little three zippers.
Wait for the tunnel, and then do the Mario at the large zipper again. Hit three of the four zippers, and go at the three little zippers next to each other. Make a little R, and a bit later start a slide. Hold that slide on and change it to an MT. Just before the finish release it. Then it's done.
0 SHROOMERS
The same, but don't use the shroom at the beginning.
Fast Lap
For low/mid expert : region 1'01"1 - 1'01"6
2 SHROOMERS
After the 1 shroomer , theres no really good shroomspot.
You could do it near the end, but the best is probably just before or just after the spiral with the zippers.
If you already doin' the R at the begin , then do it after the spiral . This is probably the fastest way.
Videos
60Hz 3 lap 2:57:633 by (Marius Mollenhauer) 1 lap 58:405 by (Gregor Fran)
World Records and Best Splits
50hz 3lap: 2'56"019, Myth A by Raphaël Ségas
50hz Flap: 57"936, Myth A by Raphaël Ségas
60hz 3lap: 2'56"816, Myth B by Marius Moritz Mollenhauer
60hz Flap: 57"956, Myth A by Marius Moritz Mollenhauer
Best splits: xx"xxx, xx"xxx, xx"xxx = x'xx"xxx