yes. you will be able to renew your card after the 6 tries. You
will need to pay for the card again for the data to be transfered
to your new card.
When you have used up the number of saves in your card, you will be
prompted to change a new card. Once the screen shows up, you will
need to insert in additional credits for the new card. You will be
able to change your Transmission from manual to auto or Vice Versa.
And you wil be able to change your tune. But warning: if you are to
change your tune for your car, all your modifications will be
reseted and you will need to modify it again.