Opening Covertible Top with Key
I ordered the Radio Key Module from Tectronics (
http://www.tectronics.com/tectronics/e_index.htm) that allows me to open AND close the convertible top with the BMW key. I installed it a few months ago and it works wonderfully. The module cost me $350.00 US and took about 2 weeks to be delivered from Germany. If you're interested in this, just remember that it only works with E46 and Z4 Convertibles with automatic tops. In the US, BMW used to allow convertible owners to open the top by holding down the "open" button on the BMW key but as of 3 years ago, disabled this feature due to safety issues. The key could never be used to close the top.
Here is how the module works. To open the top, I just click the "open" button on the BMW key and keep pressing it down for an additional 5 seconds. The windows start coming down and at that time, I release the key. Once the opening process has started, there is no need to keep holding the button down. The same is true for closing the top. Just click the "close" button and when the top starts the closing process, just release the button and the top will continue to close, and all the windows will come up when the top is completely closed.
There is a jumper setting in the module that lets you set how you would like to open/close the top. Either by holding down the appropriate button the whole time the top is opening/closing or by holding down the appropriate button until the top starts opening/closing and then releasing the button. I chose the latter since it is more convenient.
It took me about 2 hours to install the module. It was necessary to remove the glove compartment and the air conditioning panel to get to the wires. The installation is a little more difficult than installing a radio in a car so if you are afraid to work with the wirings in the car, get someone else to help or install it for you. I would say for me, from a scale of 1 to 5, with 1 being easy, this installation was a 3. The tricky parts were pulling out the face plate around the gear shift and dismantling the plack 54-connector.
In my opinion, I would say that this is the most important feature for convertible owners
. I'm glad I ordered this module.
One thing I noticed after the installation: if I use my key to open the top, my doors will not auto-lock after 5 mph. I think it has to do with the wires that I tapped into. No big deal for me though. I just lock it myself with the door close button. Now if I were to not use the key to open the top, such as during the winter season, then my doors will auto-lock after 5 mph.
As for BMW dealers here in the US, due to safety concerns, they will not activate this feature. As far as I know, it is not illeagal to has this feature on convertibles in the US (since other convertibles, such as Mercedes, do have this feature enabled on US cars) but it's more of a decision by BMW due to possible lawsuits that could, or possibly have resulted, in the past.