Coming from a background of PLC programming I personally am not scared of this kinda thing. I don't work in the automotive industry but have experience of automation control some years back
I'm a DIY'er who loves to find different things to play with and change/add and i'm totally fascinated with these BMW system , Ok i'm a bit late into this coding game but have learned a lot recently from getting stuck in. For sure it takes a lot of time and effort ( mostly translating German !!)
I'd by all means try to help someone out if I could, but there is always the risk of treading on toes and removing food from children's mouths etc hence why I suggested that help might not be forthcoming from certain areas.
There is some mileage in the 'buy it cheap buy it twice' but again cables such as you have (guessing the BT) were developed a few years back and not mass produced and since then our Asian friends have seized on the opportunity to mass market them ( Same for the Ross-Tech) of which I have a £350 Hex CAN cable sat here for work on VAG stuff but ebay are selling them for 15 quid and do the job amicably.
Down to the OP which way he would like to go , horses for courses n all that.
I just modded my post in coders to show level 2 BFD
