i am going to install a bolt in roll bar to my 95 m3 for track day use. any thoughts based on experience would be appreciated.
fer gawdsake, LOOK at the backside or underside of whatever you're drilling through for the bar's mounting plate bolt-holes! Drilling through brake and fuel lines could complicate your day!
Installed my roll bar in my E30 some years ago - started to drill a hole, then thought that I'd better check the flipside of what I was drilling into - no problem at that moment, but it woulda been a problem if I'd just gone on as the happy driller!