I was told that a Pressure test, comp test, sniffer test were all done. Apparently no untoward results. Replaced thermostat, coolant outlet housing and a few hoses. New coolant and bleed system. Told the car was good, picked it up and it cooked within 15 km of the workshop. Round 2 replaced a/c amplifier because he thought the fans were not coming on, told the car was good went to pick it up and it didn't even make it out of the driveway as they test drove it again before I got there and cooked it again.

Here's the fun part, it doesn't blow smoke, throw water out of the overflow or loose coolant. The engine temp goes up on the gauge but hate fans won't engage. Leads me to believe that it either has a hg problem and is taking air into the cooling system under boost and develops an airlock or I have a problem with flow through the radiator. I don't think it can be the radiator because the previous owner had the radiator reconditioned professionally just before I was unlucky enough to buy his problems.

Do you have receipts for the rad work?

Sounds fishy, A/C amplifier is only to do with A/C and to switch the fans in series and low speed.
 
If you disconnect the sender on the radiator fans should come on by default.
 
If the gauge goes up in temp its on the outlet to the left of the radiator passenger side. The sender is on the right drivers side.
 
I reckon the guy who sold you this car really knows whats wrong :(
 
Feel the hose on the right and see if its hot. If it isnt its not circulating .
 
 

Ok well disconnect the radiator sender. Have the key on ignition on
 
By doing so the Relay No1 will de-energise  and the fan should come on,
 
If not something is a miss check relay is operational.

Ok so feel the water outlet of the radiator is it hot ?.
 
It should be , if not its not going thru.
 
Possible the water pump is knackered also

over the years, we have had only a few cars with this mount of bother, and I fully understand the owners' frustrations
Overheating can be very difficult to find, as the 'obvious" problems are not always the only ones. The various pressure and chemical tests for a blown/leaking head gasket are never perfect. if they find "no leaks" thats not 100% certainty. if they find a leak, then that's 100% (chemical reactions dont lie) 
You cant really compare a rebuild of an engine like a 3SGTE with a bolt-in second hand 2GR. different deal totally.
The biggest problem is the cost of labour and the man hours needed. In this country, any reputable mechanical shop charging less than about $90/hour is losing money. it  takes us about 40 hours to remove a 3SGTE, overhaul it fully (internal machining etc) and then put it back in. Add to that cost of parts and $7-$8K appears quickly. I doubt many others can do it this quickly as we are one of the only shops that do it all in-house, and have spent years building special tools,. jigs etc to do these cars. 
Generalist mechanics often look at these cars and run away and hide, because other jobs are much more profitable. They are not incompetent, they just dont want your work. Taking a MR2 to these people for major jobs like engine or transmission repairs is just asking for trouble as they get caught every time. Dealership can often be the worst, because 75% of their staff have no experience other than near-new cars, and these dont have any "old car" issues like i constantly see appear on these forums 
I hope this puts you all in the picture