Problem Car setup - unable to setup gears/gearbox on any car - why??

I would like to ask community to help. I am not able to configure the gearbox, all of gear setup "sliders" on the gearbox setup screen/tab are inactive, unable to change any values. Actually I own only basic group of cars for free, no bought cars, but I supposed all kinds of car setup will be available on all cars. I went already through the forum, but was not able to find any solution/reason... Could you help me, please? Thanks a lot

 

Not all cars have the option to change gear and final drive ratios! For instance GT(R)3 - same as in real life. So this is normal and the cause of your problem.

 

Thanks a lot for your reply. I was only a little surprised that every car I tried has locked gearbox ;-). So it looked for me something is wrong...