How do you use FxCameraMap in mediatracker? There's only 3 options and none of them makes sense

Very simple actually. Place your camera somewhere where you want an image to appear on the surface. Click "take screenshot" or whatever it is called, then open any image editing software and load the image that has been saved somewhere in your maniaplanet folder. Edit it to whatever you like and maybe add some alpha channel.
Go back ingame and reload the image. Done
http://www.youtube.com/watch?v=D7RFP9Gayso
Shader must be set on Nice to work.

It's quite nice actually. Except for flickering and the fact, that it's pointless to me. Sigh, why, I need better comp. If you use FXCameraMap, you leave half of the community out of fun :/

It will probably not going to be in the full game anyway or with a different method due to the reasons you mentioned...so the whole community will be exluded...until something better comes along ^^

I really hope they will add 3D Triangles instead. Besides color and opacity, you could also set shininess. I can already imagine what I could do with this (hint: it would be pretty epic thing ). Also, it seems a trivial thing to add, maybe this should be told to Nadeo?

Actually, we are beta testers. Our job is to tell Nadeo how they can improve the game. Is there any channel inbetween community and creators?
EDIT: Umm, Maniaplanet forums might be the right way?

Sure, suggestions are always welcome in the Suggestions section of the Maniaplanet section of the English section ^^
Even in Beta2 though Nadeo developers didn't want us to write suggestions anymore for the Canyon release since most of them would be unrealistic to add considering the time constraints. You can make suggestions for upcoming titles and envis though ofc.

It looks like something that would be useful for story tracks, as well as tracks that have extremely complex routes with a lot of re-used sections. Being able to turn any surface into a sign AND being able to change that sign when you want. YouTube actually looked into this for advertisement.

I may try my hand at making a Beetle Adventure Racing style track using this and a few other tricks.

I'd want they solve the flickering :/
That tool is cool but quite annoying with flickering