Is there any way to see car and track usage statistic my month or year?
Is there any possibility to look at a specific combo usage?
I try to quickly what is popular or not. I mean training for the raceabout to play online is not very interesting as I will never find populated servers.

goto
http://www.lfsworld.net/

and login

then you can see some statistics when you click "some online charts" or "online racer stats"

Hope I could help you!

That is where I was looking for, but I am asking if there is a way to see more.

Track usage / car usage (unfortunately all-time only though)

Quote from Eclipsed :

(unfortunately all-time only though)

Yes that is the point.

Not sure if this helps but here are two very high charts showing the number of total driven distance for all cars and tracks. I was also thinking of making another two graphs where instead of total distance, only the distance driven for 1 day would be shown.

http://lfsdb.500servers.net/lfsw_stats/show_cars.php
http://lfsdb.500servers.net/lfsw_stats/show_tracks.php