Help on creating a car sensor and magentic sensor

good day, its mt first time here i really need urgent help on creating a robotic car using arduino that you can program to instantly stops when it comes near a object.
because am trying to make two cars that can never collide. if using a magnet is possible.
please i need urgent help.
thank you

Please guys I really need your help I got this project and need to submit it on or before Monday
I need to create a car and then this car must not collide with another car.. create by me. And i believe that addition can do this..
But I don't no how.
Help!!

Put them on the battery cable so the car cannot be started

Eff_jay:
Help!!

Start here. You've already completed steps 1-3.

It may help to apprise the forum of your level of programming/hardware expertise.

Many in this forum are willing to patiently assist newcomers. The words "urgent", "help!!!" and cross posting - "due by Monday" will not help you.

Seems apropos.
failure.jpg

failure.jpg

@Eff_jay, please do not cross-post. Threads merged.