Solved

Not high enough level for this

I was wandering how many levels above a driver i can buy as i attempted to buy a level 10 driver as a level 7 manager but it didnt let me

Hello Callum,
You can only buy drivers that are either equal or lower level to your team. For example, you as a level 7 manager can only purchase level 1,2,3,4,5,6,7 drivers but not level  8+. 

However, it is possible to train your drivers sot they have a higher level than your manager level. Should this happen, the driver stars will be shown in red, but you will still be able to use them in races.