Hey, you can retrofit the orginal alarm at a BMW garage. The price for the parts is about ~220€ without sunshine roof and 280€ with it. The costs of the fitting I realy don't know. I hope I could help you with this informations
Thank you for the fast answer, the point is that the BMW dealer here in my area is a very good friend of mine and told me that the original BMW Alarm is far expensive for what is offering, plus it's very simple......I could get an aftermarket one for the same money but with better specs.....