Overflow Tank
 

I ran my car on the freeway, brought it home, checked the coolant overflow tank and the fluid was in the middle of the tank. Is this normal after running the engine?

Depending on the driving, the coolant in the bottle will go up & down. But it should not overflow out of the bottle.

I keep mine about 1/2 full, and it stays there, cause I don't have any issues.

I might go into the mtns (like last Sun) and drive like a maniac, and I always stop and check under the hood before heading back home.

The level may be up, even close to the top sometimes, but then it will go back down after sitting for several hours. This is normal for these cars.