use a caribeaner and several key rings (Score 1)

I have several key rings on my caribeaner. 1 set is the car, 1 set for the home. but when I drive the car I take the house keys off and put them somewhere in the car. then when I reach the destination I only have to worry about the car keys. When you drive home put the key ring with the house keys back on and you are good to go.