Use Redline WaterWetter instead of generic Anti-Freeze/Boil.
You can get it at BNT (I know for sure, as they stock Redline). Its costs me around $20 for a bottle.
I use it in all my vehicles and swear by it now!
Check it out at: http://www.redlineoil.com/products_cool ... tegoryID=4 and make sure you watch the demo