I'm glad you were able to get it working! You might want to find a different dealership though. Quoting you $65 to replace a $6 battery seems pretty dodgy to me.

Also, one caveat on the key card; sometimes I have trouble opening the trunk when I'm using the card key. When this happens I need to hold my wallet (that I keep the key in) in the hand I use to press the button to open the trunk. This might be because I have an RFID blocking wallet which may interfere with the key. It only happens occasionally, but I thought it worth mentioning.

Very interesting thread--I appreciate all the info. This will help me while I'm shopping.

Been using the card key for almost a week now. Enjoy the convenience since it's just like another card in the wallet w/o having to lug the fob around. That said, the advantage of a card key is also its downside, in that there are no buttons to remote lock/unlock/open trunk. In all I'll happily push the buttons myself in lieu of carrying the fob. Love it...

Where can you order a replacement for the card key?

I've seen these offered on ebay--I imagine you could get one there cheaper than the dealer.

But I don't know how hard they are to program. If anybody here has done that, it would be interesting to hear how you did it.

I have seen them on eBay... the only problem there is you would have to confirm to frequency with you fob.... iirc

I have been using nothing but the card key until I accidently ran over it. Now it is dead... I am going to the dealer to purchase a new one. I saved the key to put in the card but they will have to program it with my car. Let's see how much they will charge. I looked it on ebay and saw some used ones.. Non can guarantee it will work so I did not get it.

Good luck yangstein. Let us know how much the dealership wants for the new card key.

They have that battery on line for $8.00 not really hard to fine . Your just talking to the wrong people.

Hi,

I had a serious problem with this. I have been using nothing but the credit card key for 2+ years. I broke it by running over it so I needed a new key.
Went to a local dealer and they said they can't touch K900. Only few dealers that are authorized to work on K900 can work on the car. I called the other
dealership, asked if they had the key in stock (In the system they did). I made an appointment and went to the dealer.

Non only didn't they have it in stock, I had to pay out front for the key which was $547.50 including tax. Waited for another few days and they told me
the key was in. I brought my car back to the dealer and paid another $65 to program it. It did not work. The dealer told me I could use it only in emergency
purpose where I could put the credit card key to the ignition button. I said that is when the battery is out but they tried to teach me how to use the key
where I had been using it for 2+ years. So frustrated by 3 people trying to teach me, I decided to leave.

I came home and put a new battery in it, it worked fine... I went back to the dealer and showed them how it works. They could not say anything.

The total for the replacement of the "Credit Card Key" cost me $612.50.