It may also be worth checking the rear view mirror isn't leaking ! The auto dim rear view mirrors have a fluid between the two sheets of glass inside them and between the glass is a fluid that is very corrosive , the The mirror is damaged it can leak out and dissolve the dash, it's really nasty fluid . The early E85's suffered with this issue but I've not heard of an E89 doing it, but might be worth checking , if it's leaking, remove the mirror straight away before more damage is done . Excessive heat exposure can cause a leak too . Best check just in case .