Re: wierd clanky noise on acceleration ?
Your more than welcome. How would you be 'driving it poorly'? Automatics are a no brainer to operate. The most common mistake people do is wrongly select the proper forward gear (they'll leave it in 3rd while driving on the interstate without realizing the tach is upwards of 3500rpm). It won't hurt the engine none, but fuel economy, engine wear and noise will increase.
Still, the engine shouldn't lug as you described in your first post. The dealer should have no problem duplicating the problem. While your searching the net, see if you can find any TSB's (technical service bulletins) published for your model year vehicle. It might give you some added insight on other ongoing problems if there are any.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!