I respectfully disagree.

Ran an almost bone stock M03 last season and had a great time. Didn't run up front but had super tight battles with more guys. Tried it only to prove a point than anyone can get into Mini racing and you don't need the best to compete and have a great time. Working on your driving is more important.

Bearings is just a good idea from heating up those bushings and melting your plastic chassis.

Other than that, friction dampers work, just less steering but you can drive around that. All plastic stock parts are fine, just crash less. Stock gear diff extra washer worked fine. Dogbone outdrives fine.

I think only about 0.2-0.4 seconds slower on a 10 second track indoor ozite mid grip.

Maybe an extra $50 could make your M chassis more competitive. But the rest is bling and completely up to you.

Just have fun,

Ivan