Assalamu Alaikum!
My question from you is that I have seen many vehicles in which people have tied black cloth. Is it Ja'iz? If no, then is there any sin on it or no? Please clarify.
In the name of Allah, the Beneficent, the Merciful
These are amulet worn or hung to serve as a means of protection and security against evils such as evil eye, black magic etc. It is permissible to use these amulets, however, they should not cause the user to have an incorrect belief, that the amulets are protecting other than Allah. If that is the case, then one should avoid using them .