Most of the time people will say "If you want a good tool, 'cheap' wont' work.". I have a few questions...
"All night at the track"...this means you're taking off and putting on a lot of wheels, and you need a tool that will have lasting power?
"If it gets run over..."...this means you don't keep track of your tools, or the drivers are idiots and run over stuff? Pissed I understand, I can't even see a $3 tool get scratched without seeing red...but then again that'd be OCD taking over.
You mention Milwaukee, which tells me that you want cordless and not pneumatic?
Cheap I wouldn't do. Ryobi is a great brand and is "cheap" enough that you won't shoot sparks out of your eyes if it gets killed. I love all of my Ryobi tools. However, if I'm reading your criteria correctly, you want something along the lines of the
IR IQv series...plenty of balls (without a doubt), strong enough to take a beating (even possibly getting run over), and plenty of long-lasting power to get you through the night. Not cheap, nothing good ever is, but would probably fit your needs perfectly, and after time you'd forget about how much it cost.
I use the IR W7150 at work and it's a pure beast in terms of power, ability, battery life, etc.. Maybe a bit overpowering for lugs, but "big balls at the track all night long" you might want that power and battery life...could make a difference in your abilities to pull wheels effectively where other tools or "cheaper' tools might not last. There's a good lineup of tools in the IQv line, you might find one that fits your needs perfectly and doesn't hurt your wallet too much.