Don't take this the wrong way Maruzo but you might want to consider the cost of keeping the factory system (upgrading it to add what you want and repair cost of what isn't working) vs the Seicane.
The reason I am mentioning this isn't to try to talk you into the Seicane or one of the other aftermarket radios as much as pointing out where you will be if you succeed in fixing and upgrading the factory stuff.
When I bought my e53 I wanted to stay 100% stock. It had factory nav, Bluetooth, cd changer etc so it had the components I needed except the backup camera.
But the screen was failing like they all do and needed replacing $125 and the effort to do it.
I needed a backup camera which needed the tv module so I was looking at $200 to $300 there all said and done.
Then I found out the Bluetooth module was bad and killed the battery so I replaced it with one off ebay $90 or so.
Then it failed after 2 weeks killing the battery like the old one. Not to mention being very picky about what phones it would pair with and was a pain to get it paired.
So I was looking at another $90 to $100.
So at this point I am looking at $525 or more just to get it all working like I wanted with a backup camera.
So $525 and I have a 13 year old sound system that I cant buy ANY new parts for and will be nickeled and dimed to death cost wise by being forced to buy used parts forever......
Hellllloooo Seicane. $300 and a $30 backup camera and done.
If it dies and vanishes from the dash Im out $300 for a new radio from them or another manufacturer which will be new and have all the latest bells and whistles at the time I buy it. So as long as I get 3 to 5 years service from it I can have a new radio for free over the cost of keeping the factory stuff alive with used parts.
That's how I figured it up and that's why I ditched the factory stuff even though I really wanted to keep it to start with.
I have no regrets that I ditched it now but I really didn't want to go aftermarket on the e53. It just worked out to be the most economical choice since ebay was going to be the only supplier for parts for it
