Here is the number placard required to be worn during championship events (per the official SimRS rules).

Any driver not bearing the placard will likely be excluded from any promotional photos/videos.

And where exactly should it be placed?

Quote from hackerx :

And where exactly should it be placed?

On your shirt...

Good question. One on each door is all that's required.

I suppose you need to put the same number as you gave in the registration (portal)?

also can i change from fz5 to rb4

Quote from Aquilifer :

I suppose you need to put the same number as you gave in the registration (portal)?

Yep.

Quote from james12s :

also can i change from fz5 to rb4

I've removed your entries from rounds 1 and 2. You can just re-enter choosing whichever car you want.

ok thanks mate,

i think you need to ad a withdraw button

Quote from james12s :

i think you need to ad a withdraw button

Good idea. I haven't fully developed the Portal yet, but that'll definately be on the list.