Solved

Driver contract extension

I move to Help & Support subforum.

It's completely fine unless you do not renew before his last race in that contract. So you can renew when you see 1 race left in the contract.

Otherwise you will be given a random 1 star driver. With your former driver out of the team.

If you want to keep that driver you need to renew his/her contract before the last race or he/she will leave your team. If that happens you'll get a low level driver unless you have already a replacement in store.

If you renew the contract the driver gets a 10% pay rise, however you do get to sign him/her at that salary for 50 races. 
A new driver will need re-signing after 20 races and a 10% pay rise.

I once forgot to sign my best driver, he left, it cost me £10m to resign him, a huge pay rise and a 20 race contract instead of 50.  

I thought you needed to renew their contracts no later than 2 races to go? Or is that staff?  
Good question Chaz.

Staff and driver's contracts work the same way. I think you can even renew them during the last race. Never tried that, though. I always renew their contracts at the end of the penultimate race.