How strict are the rules for modified cars these days?

I bought a used car recently that has some modifications from the previous owner like a different exhaust and slightly larger wheels. The car runs fine and looks good but I am nervous about taking it for inspection because I dont know if these changes will cause problems. I have been researching and understanding roadworthiness standards in the UAE because I know modified vehicles sometimes face extra scrutiny. Some people tell me that as long as the modifications are not extreme and the car passes emissions it will be okay. Others say even small changes can get you failed if the inspector is in a bad mood. Has anyone here passed inspection with a moderately modified car? What should I check before I go in to avoid a nasty surprise?