There have been isolated incidents of the version which uses the OEM key fob behaving erratically and over the past couple of years both Duncan and I have been trying to understand why that occurs and therefore how to rectify it. We know it has something to do with the BMW designed security system but have not, as yet, been able to come up with a work-around that I would be prepared to recommend, although, I'll certainly carry on researching
I have now decided to admit defeat, in as much as, I will not recommend the OEM version for the foreseeable future and will ask the Admin here to delete the How-To associated with it. If anybody desperately wants to use the OEM fob, then they can contact me and I will happily provide the How-To, on an individual basis, caveat emptor, as it were
To be frank, I have used the third party remote version on VeeKay now for several years and it has been rock solid in terms of reliability and is actually more convenient.
For example, there are times when I park the car extremely close to a wall and therefore retract the mirrors prior to parking. It is therefore convenient to use the OEM key fob to lock the car and also to unlock when I return, knowing the mirrors will not extend and hit the wall.
In addition, the third party remote allows Mk1 cars to have remote boot opening and still leaves another channel for future development.
The Quasar Electronics kit that I use myself and recommend is very high quality and, as already stated, totally reliable and, in point of fact, the rolling code method it uses is more secure than the OEM version It can be seen HERE
I would like to point out that I have no connection with Quasar, other than to appreciate their products.