tire pressures for maximum all-around grip

I've been playing at the autocrosses now for a few months with mine. if you drive your car even close to the limits - 34/38 is NOT the way to go! You have a severe risk of the tire rolling off the rim at high speed hard turns - not pretty for your wheel, tire, or the rest of your car. My first autocross - I ran 38/40.... this was as low as I would rec going - the grip was nice - tire wear was severe - especially on the fronts. I have since been running 42/45 cold. Not as much wear - almost as much grip - virtually no chance of a tire removing itself. The Rec tire pressure is there for a reason - too low - you could lose a tire easily - too high (and when they heat up) you could have a blowout. stick within a few notches either way. Even the pro CCAers and autocrossers couldn't rec lowering too much (in normal situations - with smaller wheels and larger tires - they said it would be less likely to roll a tire - but with the extremes the M5 are set at - huge wheel, tiny tire - they didn't want to be responsible for sending me poor (or uneducated) information causing me to lose a wheel or worse. If there are any people out there - that have a real rec for autocrossing - someone that REALLY know's the answer - please pass it on - cause if I can lower the pressure some - with little risk to me or the Mach-5 - I would prefer the grip. (airport tarmac is real rough on tires to begin with!)

Please Help!!!!! (no offense to Craig - those settings are most likely good for 9/10ths of driving needs - it's the 1/10 you might hit at a driver's school, autocross or track event that I'm worried about!)

Cheers,
Sean