YOU SAID:

i cannot find the keys to my car

INTO JAPANESE

私は車に鍵を見つけることができません

BACK INTO ENGLISH

I can not find the key in the car

INTO JAPANESE

私は車でキーを見つけることができません

BACK INTO ENGLISH

I can not find the key by car

INTO JAPANESE

私は車で鍵を見つけることができません

BACK INTO ENGLISH

I can not find the key by car