my car keeps overheating

You seemed to have replaced everything but the coolent. Replace the coolent. If that doesnt work, then your line maybe clogged.

I replaced the coolant twice. How do you unclog the line?

If this was in my bay I would proceed as follows: Repair fans: It will overheat at idle without the fans. The first test for this is to turn on the A/C, both, one or none will come on. Test and repair as needed. Test for system flow: Remove the inlet hose to the heater at the firewall. Test pressure and flow rate. A lot of water should be pushed out when the engine is revved. The pump should make at least 10 psi. This gives the relative heath of the water pump. The most common cause of poor flow in a Subaru is air trapped in the engine block. I would flow test the radiator and visually inspect the radiator interior. The flow tests is not very helpful. A radiator can flow great but not transfer heat if it is fouled with coolant scale deposits. From your description i would repair fans first, replace the radiator, put it all back together. Test after repairs by timing the fan run time. If the fans are off most to the time and the fans run only about 20% of the time and the fans blow warm air it is fixed. If the fans run most to the time and the air coming out is cold it is not fixed. A quick test to see if you have adequate flow is to touch your upper inlet radiator hose and the lower exit radiator hose. If the upper hose is hot and the bottom hose is cold, you May have Inadequit flow. Worst case scenario, you will have to replace your radiator.

Thank you I have replaced everything except for the radiator. It looks worn and dated and looks like it has a lot of sludge or rust build up. Thank you

The radiator has a plug at the bottom u can unscrew and drain out the old water and flush it out with a hose....you can use purify water or rain water in the radiator to prevent clog...and also make sure the side gallon for the radiator water is not over filled bc that can cause overheating make the water can't circulate fast due to too space pressure from the heat...

I replaced all others have. Two mechanis and $6+ plus later still overheats. One suggest bad engine\motor. How is that possible?