URGENT Design of next seaons car stopped, help!!

am focusing a lot of my designers on next seasons car, but i have have got to a stage where the process is almost complete, but in my last 2 design e-mails there has been no work done on next seasons design just a small improvement with my current car.

This has happened twice now, and i am just wandering if i am doing something wrong or is there a fault with the design process.

I only have a couple of races in this season to go and would like to get my car done for the following season, or is this something that the game does inbetween seasons if so how much of your car do you have to have designed by the end of the season to have it finished for the following season.

Can someone help me please.

It may be because your "maximum performance" level has been reached. On the design page look at the top right, I believe this is the maximum that any single part will be able to reach in terms of performance. If you train your design team to be better the maximum will increase, there are probably also other ways but thats all I know of. 

I have an issue with my design for next years car. I have 1 race remaining of this season and have only achieved around 18% performance on next seasons parts. I kept all my focus on the current seasons car till around half way through and started to shift focus to next year progressively as the season went on. Did I simply leave the focus on my current car too long or does the ingame balance need looking at to give more performance for next year? My current car isaround 70% so it doesn't feel entirely balanced to me.....but I'm biased :)

it's your choice of where to put the performance. If you want it balanced - it's up to you.