I tow a 3000lb trailer fairly regularly, no concerns, The hitch looks pretty good back there, (mind you, every truck ive ever had has had a hitch!)
the trailer module is a pretty key component. It provides turn signal info (at the minimum) and switches off the pdc back there when a trailer is on. i do keep it in sport mode, and tend to use the manual mode to keep revs up when i go up hills etc. for the most part, i havent had any issues. the standard tranny cooler seems to be enough! (so far!) I will be looking to install a trailer brake system this spring too, for now, its fine!

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2003 X5 3.0i (02/2003) sport package, Sapphire black metallic / Black Dakota Sport seats. compass mirror retrofit, trailer hitch retrofit, Prodigy P2 trailer brake controller installed, PDC retrofit, Lumbar support retrofit. heated rear seats retrofitted. Running boards retrofitted and subwoofer install in progress. 4.8is Brakes installed front and back. Bluetooth TCU installed, Rear Fog lights installed. Retrofitted reclining rear seat backs.