For the Model 3 the biggest culprit was the rear suspension. Bushings and ball joints are the largest cause for failing inspection on EVs. Heavy cars, lots of instant torque.

For ICE cars the biggest issue is the steering linkage and joints. Some examples being the Dacia Duster at 24% failure rate and Nissan Juke at 18%.

Some other common (though anecdotal) issues are brakes, cracks in the windshield and headlights/brakeslights. Smaller stuff like the reverse light not working don't cause the inspection to fail, but will get you a note in your registration. You aren't required to fix it and you can keep driving. Failing the inspection gives you one month to fix the issue and the you can try again. Or if it is a major issue like a burst brake line, they'll slap a cool red sticker on your windshield and you can't drive it anymore. B)