To add to the above comments, the E70 came out in 07. The biggest difference was inner and outer cosmetics. I personally do not like the interior (I call it minimalist eclectic), but do like the exterior changes. I-drive is crap in the new E70. It is also slightly larger than the E53 it replaced. The current X3 is roomy enough for 3 dogs, but it will be tight. In additon, you can get a 3rd seat in an E70 that was never available for the E53. I came from 3 previous V8 BMW's to my current 3.0 X5, I can say that for daily driving the straight 6 does just fine and you will appreciate how smooth and quiet it is over the V8's. If it's torque that get's you going, then stick with a V8. I would look for an 04+ if you go with the E53 since it has the newer X-drive and options like Bluetooth and DVD based Nav. Stay away from 07 E70's, there were a lot of 1st year issues. There are some very good deals on E53's right now.