Volkswagen: 2000 VW Beetle overheating, coolant level, electric cooling fan

Question
My 2000 VW Beetle overheating dummy light comes on after about 5 mins of driving.  Checked the coolant level and it was topped off.  Oil just recently changed and also topped off.  Initial overheating was about 8 months ago, put coolant in and car has been fine, using A/C and all- then about a week ago started it up and drove 5 mins, then pulled in the driveway and liquid was running everywhere.  we could not find any hoses busted, so don't know how the liquid was running out.  Replaced the thermostat and topped off the coolant fluids again but that did not help.  Any suggestions?

Thanks

Answer
You may have a busted engine head gasket.  Doesn't make sense if the car's been driven 8 months since the first instance.  But if so, there's also the possibility of water mixed in the oil, very bad.   
 Perhaps the electric cooling fan is not kicking in.  Then the overheat situation develops and coolant may be coming out the radiator overflow tube.
 My first guess would have been the thermostat, except you state it's been done already.  However, some replacement parts are inferior and fail quickly, something to consider.