I mean race loser, not loser loser.

Don't feel bad. I'm mostly a loser too - but I had fun building cars with my boys. And I'm not bitter.

My boys did all the design work. I used any power tools necessary to shape it. Most of the time my boys' cars were primarily a single color, so that meant spray paint. Sometimes they did it, sometimes I helped. Any stickers or other items added, was all on them.

I figured since they hadn't mastered using a soldering iron yet, that that's how we put most of the weight into the bottom of the car, that was on me.

And I'd usually do all of those little "extra" things with the wheels and axles to make them smooth and ready to roll well before we attached them together. Usually I'd hold the axle in place while they gently tapped it in with a small hammer.

I think it's totally fine/acceptable for the parent to be involved in some of that finish work, as long as the boy is involved too. I don't recall necessarily being first place all the time, but I was just aiming to not be last place and making sure my boys' cars were competitive with their buddies as they raced. Usually they were.

That said - I get where you're coming from. Always made me laugh when there were those handful of kids who's fathers would hold the car for them and carefully graphite the wheels between every race while not allowing their kid to touch the car until the races were over.

In our area, they did away with the actual competition and naming anyone champion. They'd just turn the kids lose on the track and let them take turns racing each other. In the end, the boys all knew which car was the fastest and beat everyone else. And everyone got their own certificate for "most unique", "best paint job", "most futuristic", etc.