Hi. I don't post here but have been lurking. I was hoping for some help/advice. We just sold our 325 so the search for our X5 begins. My question is the durability of the 3.0 vs the 4.8. Can anyone enlighten me as to any concerns or issues I should be looking for? I'm also concerned abot tranny issues as well. Thanks for any help. Btw, I'm leaning toward the 4.8.