I specifically bought the 163bhp version with manual box (boy, am I glad not to have gone for the auto judging by reports of short lives in that box!) Done two long tows into Southern France with my Burstner 430TN caravan -1350KG weight. Absolutely rock solid and will tow in 6th on the level at motorway speeds up to 60 mph (British legal limit for caravans under tow). Got 32mpg with no bother and the huge tank helps to ensure long distances between fill ups. Very quiet under tow except when having to give some "wellie" when needed. A friend of mine has the tow bar which does a disappearing act under the rear bumper at the press of a button - very expensive. I have a Towsure detachable which cost me £600 in early 2015 with 13 pin electrics as the Burstner has that for standard.I've been towing with a 508sw 163bhp allure for about 18months now with no adverse issues. I tow a Bailey 4berth 7M van which the 508 handles with no problem.
I previously towed this van with a 2.0L Mondeo, which I think is acknowledged as an exceptional tow car and the 508 is every bit as capable.
Peugeot ones are ****. I've replaced them with normal bolts on every one I've had.Locking wheel nuts.