Sorry, your message is confusing as it is one long run-on sentence.

You place items in the trunk and closed it up properly. After entering the vehicle the car "unlocked" the trunk.

What do you mean the car unlocked the trunk? I am going to assume you mean "opened it" since there is no "lock" per-say.

The lower lid has a manual release handle. The upper lid has an electronic release. It should never "pop open" by itself.

This has never happened to my X5. Take it back to your dealer so it can be inspected and corrected.

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2007 4.8i, Space Gray, Dark Burl Walnut Wood, Black Nevada Leather

Packages:
ZCW Cold Weather, ZPP Premium, ZRC Rear Climate, ZSP Sport, ZTP Technology

Options:
217 Active Steering, 322 Comfort Access, 328 Running Boards, 496 Heated Rear Seats, 610 Heads Up Display, 655 Sat Radio, 840 Increased Top Speed to 150 MPH ,2LE 20" Y Spoke Wheels.

Mods:
Stainless Steel Pedal Pads