I did really bad in my GCSE A'level (As) this year! I need to retake. But I need to know how this is going to effect my University admission!

Honestly, with the current squeeze on University places, you might be better off looking at an alternative route.

What subject are you interested in studying ?

At the moment I'm studying Physics, Chemistry and Maths!
I'd like to do Automobile Engineering or Designing.

But yes I'm able to do Engineering I'd probably try out for designing as well!

But yes I'm able to do Engineering, I'd probably try out for Designing as well!