I'd like to know more about this, if you don't mind elaborating - keeping in mind my relative machanignorance I often can go a month without traveling more than 2 miles/trip from my home. If I buy the unit you linked: Amazon.com: Clore Automotive ES5000 12 Volt Portable Battery Booster Pack: Automotive I should be fine (even tho my SA recommended driving 20 or 30 miles at least every 2 weeks).

I cannot help but wonder if this is a problem on all BMWs or exclusive to the X5. Mine is not diesel so I don't have glow plugs. But, I do hear a bunch of stuff kick on whenever I open a door. Mine is also a comparatively low build with only Prem, tech and heated seats as electrical extras. Other X5 (and other models) often have way more electronics. Also find myself wondering if this issue is truly statistically prominent or an occasional glitch we see as forum followers. X5 has certainly suffered reliability ratings drops but then again, Service departments are pretty quick to claim "driver error" for things like opening doors too.