Mecahanical

At "high speeds" your engine is working its hardest, so any deficiencies in its cooling system are going to cause some overheating. Lucky for you it does not appear to be head gasket related. I would check the following - radiator cap (they should be replaced every two years anyhow), thermostat, plastic air dam under car, radiator, and finally water pump. A radiator can be checked with an IR gun, you want to see entire radiator is warm, without any 'dead' spots indicating blockages. The air dam, if present, aids in directing air up into radiator. They often get knocked around over the years or even torn off. At low speeds they don't do much but at highway speeds they help with air flow to radiator.

I'm thinking it is the radiator blockage. I think if it was the thermostat there would be problems with the heat. The water pumps rarely fail on these cars though it does happen. However when they do fail it's either of bearing which makes all kinds of Racket and your car will not run at all without overheating or it's leaking and you will see fluid everywhere I have seen no leaks. However the bottom radiator hose is significantly cooler than the upper. I'm going to undo the top radiator hose and check that the water pump is pushing out a good stream through it. My air dam is intact that is actually the first thing I checked. Any more input would be appreciated