It would be nice if someone can make a key fob that looks exactly like the new bmw keys but have the flip out of the main body like the new VW keys

 

I was thinking if you used an old / donor (via flea bay) VW flip key you could take the mechanism / spring for the flip, but this will involve some form of welding to marry the bmw metal key with the button (be it metal or plastic) as Im not sure how easy it is to get a blank cut without involving a stealer.

You would then need to dremel the side of the OEM new style key and some how place the flip mechanism / spring in it... would be an interesting project but could get very expensive and I would not even think of attempting this without having a spare key

So anyone going to try making one?

 

Very good guide, a good starting point

 

This was the first thing that popped into my head when I first bought the car. Has anyone tried these from ebay? I'm thinking of getting one but I'm not an electronics expert and could use a lot of help. http://cgi.ebay.com/ebaymotors/FLIP-...Q5fAccessories

 

It can't be this easy can it? http://shop.accessory4you.com/05-cha...-1.asp?id=2407

 

Interesting; thanks for the input. This is defiantly on the right track and actually does answer the design brief initially set up to an extent. By looking at the photos on the ebay link, it appears that:

[1] You get the metal key sliced off. Attach it to the pin case like it shows on the photos.
[2] Put in the 'guts' from the donor key.
[3] Bob's your uncle; ready to go.

A few reservations I have with this:

[1] Build quality and materials seem poor. It would be good if the case could have been a customised OEM unit or at least of OEM quality.
[2] How secure would the internal parts coming from the donor keypad be? Are they free to move or fixed in place? How secure is the metal key, will the poor build quality, (or my perception of), be able to stand up to daily usage and turning the key?

Just my two pence.

 

Ok, I found this http://forum.e46fanatics.com/showthread.php?t=498843

It appears that they discovered that the transponder is the 8-pin IC at the bottom.

Can someone educate me on how the transponder works? I apologize if this is a stupid question, but I really want to try this out. It's just a radio signal from the car to the chip on the board right? So I can theoretically take my working circuit board and battery, and place it into that ebay key fob (once its cut of course)? I don't see a direct metal to metal connection from the key part to the board which is ok? I can start the car still?