Rim Size

[I CU2]

Now the thing is, the 04 cl9 lux came with 17 inch rims....so my question is, easily signed off by honda without the need for certificates and all that bs?

Nope, you'll still need an Engineering certificate (Make friends with an Engineer?). It's based on the car you own regardless of other variants. What were the original sized wheels on your car?

It's a bit silly, a base Aurion has 16" wheels meaning you can go up to 18" in size. A TRD Aurion has 19" wheels meaning you can go to 21"s...