Don't feel like grinding hundreds of Play Coins or deleting every tall Mii off your system, but still want to go fast? This guide will show you just how to do it. But first you need a couple things:

¤ A 3DS with the special Miis of either Junichi Masuda or Aya Kyogoku ¤ At least one additional 3DS system

1: If you have any StreetPass tags, clear the queue. You can use them as normal, but leave at least one game alone (with the red "!" circle). Put the system into Sleep Mode.

2: On the additional 3DS, create 9 short Miis. It helps to name them with a number for later. Depending on the number of 3DSes you have, you can make fewer Miis across each, such as 3 Miis on 3 systems.

3: Open up StreetPass Mii Plaza on the other systems and set the Mii to one of the short ones. Check the original 3DS has StreetPass, but don't go to the Plaza gate.

4: Change the Mii on the other systems, then wait until the original 3DS is StreetPassed again. If you named your Miis by number, it makes it easier to figure out who you've sent. The refresh rate for two systems to StreetPass is 8 hours, so be patient!

Repeat this step until you have EXACTLY nine Miis queued up on the original System.

5: From here, go to the Plaza Gate, welcome in the nine short Miis, then open Slot Car Rivals.

6: Unfortunately, you'll have to grind for Masuda or Kyogoku. It's only two Play Coins at a time, though, so it could be worse. If you get someone other than those two, DO NOT RACE WITH RIVALS. Quit back to the plaza and try again.

7: Once you get the right Mii, head into any Race with Rivals and finish it. If everything went well, congratulations! Now you have a Rare Booster with +19 in Speed! Enjoy your newfound velocity!