Suggested

Testtrack

I miss a testtrack for testing my drivers up agsinst each other, effect of training and other stuff.

The coolest would be if it was possible to have a training section on every track then you could take a stint and see how much the usage changed from Max Fight -> Fight -> Neutral -> Push -> Full push

I know weather and temperature will having a effect but more data you have the bigger advantage you get some times 

I think you are forgetting a teeny tiny problem with private lobbies...

They need multiple managers in it to start, which means you would need to coordinate with others just to quick race in a track to gain data.

Not entirely true.  If you have more than one account you can race/test between these accounts.  I used to do this when I needed to know how tyres would react at particular temps at certain tracks and to determine optimal pl 

Thanks. I'll test that :-)

I think the idea of having a test track should be more linked to issues of development of the car itself than in relation to the drivers, as is done at GPRO, for example.