Is there any way or option for me to have vibration on my gamepad (XBOX360 wireless) ?
Simple answer no / yes would do it. If "yes" - please support me how.

Nope, not possible natively with LFS.

I found a software that tried to emulate FFB on the gamepad once, but it work like s***.

Just wondering if it's hard to do, or.. any reason why it doesn't?

Simple, LFS doesn't have proper/real gamepad support.
I don't think it's hard, but it takes time, and it's pretty low priority (even if it would be nice), so I think it's really not for the next updates.

Thank you for answer.
Edit: spelling.

This is kinda out of topic, but Logitech F710 gamepad, which is also wireless, it's vibration works like charm!

So, what I mean is, there should be something properly done for having correct settings for 360, unles... ( dunno )

Once you said that, if I remember correctly that my F510 (old controller) worked ok, but XBOX doesn't. Just wondering, if it's just me.

Tried your tip, virbation works, but controller disconects itself after couple seconds. Strange.