Unless your car uses a recovery system (reservoir tank), then that is normal. Older systems are designed to run with 1 to 2 inches of air at the top of the radiator when cold, that is then full when running from heat expansion. If there is excess in the radiator, it will puke out on shutdown, suck in air, and stay there. After a couple puke sessions, it should remain at the same level from then on (unless it gets hotter sometime). Checking coolant in your car becomes simply removing the cap (when cold) and checking coolant level by eye or finger dip. HTH
David