GUESSING GAME

Believe me when I say it's not easy being me
I will give you some clues who I shall be
Kept on a ring sometimes maybe a chain 
Only come out when needed once again 

Without me you wouldn't start your car 
Entering a house I then become a star
Sure I have friends with me in a bunch 
Often alone would also be my hunch 

Have you dear friend guessed my identity?
For I am your friendly metal and trusty key 
Did you get the answer right from the start ?
For you will always have the key to my heart