Please help diagnose, give me some direction here...

Finished the install on the short shifter...

Car warms up to operating temp
Drive 5 miles
Stop at Sears 20 minutes

Start the car and the coolant light comes on immediately!
Shut the car off immediately and pop the hood. NO coolant under the car. ALL hoses leak free. I pull the pressure release lever on the AST and hear coolant being sucked from the overfill tank. Car cools 5 mintues...I pop the filler cap...coolant level about 1 inch below the filler neck.

Start the car, turn the fans on, drive realllly slow home with my eye on the temp the whole way.

In the garage car cools with fans and external fan for 10 minutes. Open filler cap...NO COOLANT there...AST is full...overflow is full.

Help..?

Thanks!