I bought q300 for my Lexus Is300 and came with 2 metal rings and 2 flange gasket. What are the 2 metal rings for? Do they go inside the flange gasket? Also, it was missing the lock nuts, can I use the original nuts on the car or these are welded?

 

When I installed mine, I didn't use the gaskets or metal rings.
You can re-use your OEM donuts and the Invidia nuts and you're good to go.

The OEM nuts are welded on the factory axle back, so just undo the bolts.

 

That is what I end up doing. It all worked out.

 

is this the Invidia q300 quad tip listed for the RC350?

im looking at doing something similar on my 21 is and just wanting to confirm it fits.

 

yes, this the q300 for the rc350.

 

Awesome thank you!

As for installation, besides what you had originally mentioned above, were there any fitment issues or is it a straight fit?

 

Straight fit without any issue. This was my first time installing catback exhaust and it only took me about an hour by myself. Enjoy the random exhaust pop!

 

Make sure you don't have any leaks.

Yes people do the Invidia RC350 axle back or the Tanabe Revel for the quad look.

-Josh