if your card is due to be changed as it about to expire,and you can get done for have two card in your name what will happen to the card,do you keep it for the data that’s stored or does it go back to DVLA and there will issue a new one,
and the 28 days of data how would you show that data for the last 28 days if your card goes back would you be commuting an offence for not have the correct days of data 
The offence is ‘having two VALID cards, at the same time.’ As your card will expire at 23:59:59 on (for example) 19/08/2010. Your new car will not be valid until 00:00:00 on 20/08/2010, so you do not have two VALID cards in your possession as one doesn’t become valid until the other has expired…If you get my drift.
The requirement is that you produce your driver card at a roadside check, so it could be argued on 21/08/2010 that if you produce your current card (the renewed card) then you have complied with the legislation. Probably a good idea to carry your old card with you until it’s expiry date has passed by 28 days, that way officers can see what you have done in the usual 28 + 1 day period.
Make sure that your employer has downloaded the data off your old card, you can download stored data from an expired card, just not write any more data to it. Then securely dispose of the card (shred it, burn it or eat it), it doesn’t have to be returned to DVLA.
DVLA will should send a renewal pack to you upto 3 months before your current card is due to expire. But it is YOUR responsibility to apply in time, not getting the pack will not be a defence, just like not renewing your tax disc 'cos you didn’t get the form is not a defence now. Provided they receive your application to renew at least 15 (working) days before your current card expires, they MUST ensure that you get your renewal card before your current card expires. The renewal card will be sent to your home address. If your application gets to them less than 15 days before expiry date they are under no obligation to issue the renewed card before the current one expires. Suggest you use Recorded Delivery.
Hope this answers all the questions
thanks geebee45 
just thought i would ask as i like to know