Thank you! :)
*spoilers!*
You need to find duct tape first, then you can attach various items to the RC Car. I assume you got the first puzzle completed since you found the mini flashlight. Then you have also found the audio cassette, which gives you an answer to the second puzzle. There is another locker in the room which requires a password, and the password can be deduced from the audio cassette. It can be listened by using the radio in the room. By completing this second puzzle you will get the duct tape.