Super Arcade Racing

All 100 wins must be publicly done through Find Players. Any wins attained privately through Invite / Join Room do not count (despite it seemingly unlock the trophy for your first win).

The online community is pretty quiet, and you can even limit it to PlayStation gamers only in your Settings to make it even easier to match up with a boosting partner if you wish.

The quickest way I found was to race on the very first Story level (scroll down past the multiplayer maps to locate it), it only takes about 20-25s to complete. If you're boosting with an alt account on a second console, once you've crossed the finish line with your main account, you can press , , at this point to make the alt exit the race. Shortly after, press to search again - all without needing to look at the screen!

Rinse and repeat.