Long story short I'm in the process of installing new bushings in my rear due to clunking. I was picking up the lug nuts after removing both tyres and notice that the lug nuts on the rear passenger side was different to the three other sides on my car.

Ironically it was this rear passenger side with the different looking lug nut that experienced all the clunks and there was quite a bit of play when you jack the car off the ground and using one hand push the wheel with the other hand pulling it.

Lug nut on the left photo is the one I have on 3 other wheels, and the one on the right is the one I believe is the wrong one so is this correct?

 

that is correct, they were replaced and the chrome cap was probably bottoming out on the stud, so the prior owner thought it was tight when really there was a bunch of slop. That also would give you a clunking sound similar to a bad bushing or mount. Additionally, I'm willing to bet dollars to pesos that if you put the proper lug nuts on there, the clunking disappears.

 

Ok does anyone know the correct lug nut size?

 

Both of the lug nuts in the pics look wrong... The ones on my car look like the one on the right, but not as tall.

 

My lugs look like the one on the right but nice and chromed.

It is good that you're asking since recently someone lost all 4 wheels off their FD at the beginning of an autocross run. A shop sold him the lug nuts and they installed fine but it turned out they weren't quite right.

Dave

 

Again does anyone know the correct size or a picture of it? And yes I have seen that video.

 

Any 12x1.5mm lug nut should work, most auto parts stores will carry them. If you want to make sure you don't bottom out the nut, get the open ended kind.

-Andy