Firstly, prashantrchauhan congratulations on passing your test. Have you done, or are you planning to do your Pass Plus?
I have a few students who practice in other cars then when they get back into my driving school car (also a Focus) it seems a bit strange but they all eventually can jump from one to another with no problem.
After you have done what Von has suggested (and definitely practice the braking..not just that they are working but for performance as even in my new Focus the brakes cut in slightly later than than in the old one) , carry on going by the 'feel' of the car. I have a deaf pupil whose been through various car changes with me. She can only go by feel and she can't even hear engine, has it off to a "T" with her pedal power and gear changes!
Older cars may be a little more 'tetchy' so just go somewhere quiet if you can to practice and feel comfortable. Build up your confidence and you'll be fine.
Good luck
Lynne
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