Crazy Chicken Kart 2

This should be the last trophy you earn. You will only have 8 races after completing the 2 Championships (unless you somehow lose, but that's unlikely), so there will be another 92 to grind out. It does not matter if you win or lose, but you will have to finish the race. You do need to lose 50 races, so I would suggest getting that out of the way first, then just win races til this pops.

The quickest route will be to grind this on the Factory level, since that takes only 1 minute to complete if you win, and about 1:20 per race if you are aiming to lose. Set the number of laps to 1, AI to 4 and you're all set. You can restart the race from the results menu, you do not need to go back to the menu between races.