[alexaedita]

Hello fine people and fellow BMW owners on this forum.

I am a new person here, please take it easy on me, I do not know much and really everyone's input would be definitely appreciated. I reside in Logan, UTAH.

Recently I acquired a 2010 BMW X5 30I with 118K on it. Interior and exterior on this car is simple phenomenal considering the vehicle age, but some mechanical items have to be changed/repaired/upgraded.
My intention is to keep this car in a very good working condition for the next 5 years and use it as a local family car (5k a year roughly) and take it easy on it.

Both serpentine belts were old and cracking on this car, so I replaced those. (AC belt, Alternator Belt). I have done radiator flush and fluid replacement, same with power steering fluid.
Next on my menu is a transfer case VTG leak/sip. Mechanic wants 1600$ for this repair. I am inclined to get it done, since this is essential part for all wheel drive system to function properly. I have purchased BIMMERCODE and BIMMERLINK apps and can see that there is a sensor warning code for transfer case oil wear. I guess the only question is if the price mechanic proposing is reasonable or not.

Besides that, there is no clear record of when the spark plugs or/and transmission fluid has been changed the last time on this vehicle. Previous owner have kept this car for 17K miles and only did breaks on it and nothing else. Experian Carcheck and Carfax show services being done to this car at regular intervals by the 1st owner (I am being the 3rd) for up to 100K, but the verbiage for those services is very vague. I wouldn't have a problem doing both of those things for the good of the car, but the transmission fluid change is very pricy. Mechanic claims that he needs to purchase 9 liters of special trans. fluid which is like 90$ a liter from BMW. So, it might end up being a 1000$ investment for me. Spark plugs are cheaper (400-500$ out of the door), I think I will just invest in them and put them in. Could you please make an input on these costs and repairs? Also, what data can I use/extract from BIMMERLINK APP to see if any of these repairs are needed? The only error codes that I see on this car right now are A6CF/E729 (AUC SENSOR - signal or value above threshold/signal or value implausible) and the transfer case oil wear one.

Thank you for reading my long post.