Hydroplaning

["WM" <molux@xxxxxxxxxxxxxxxx>]

I have a '91 e30 with new Michelin MXV4's on the front, and some slightly
less new Goodyear Eagle HP's on the rear.  Driving home on the Jersey Tpk in
moderately heavy rain, felt slight loss of control once, and took it easy
for the rest of the trip.  I was being passed by many other cars, with
inferior rubber and reputations.  What is the deal with hydroplaning and
safety in the rain?  In dry conditions, I feel untouchable in the car.

A few months ago, I was on the same road with much heavier rain, and with
the HP's up front, mounted incorrectly vis a vis the direction of rotation,
and some older HP's with about 3/32" tread on the rear.  At about 55 mph,
felt a shudder, and I decelerated to about 45 mph.  20 seconds later I was
spinning around in place and then vectored off the hwy onto the shoulder.
Busted tie rod and banged up lower skirt/fog lamps/oil cooler.  More
importantly, lost confidence in the car in the rain.

Where can I find out more about the situation?  Any recommendations on
driving schools to teach techniques for safer driving in tough conditions?
I felt worried driving slower than the flow of traffic.