I would be interested in this for an automotive application any way to get over the overheating issue?
You reduce the amount of time that current is flowing through the coil (the "dwell" time). It should only be energized for a very short period before you switch off the current / create the spark. Just take a close look at your distributor and you'll see the the breaker points are only closed momentarily.
There are special purpose IGBTs/mosfets designed for this type of high voltage current switching; a dig around Fairchild Semi's site will list a number of them. Or use the google, etc.