No I haven't had any problems with mine. But, I've been reading that people who do off road or have a shell or rack on the back the bed flexes and causes issues. I've got a try fold soft tonneau that's and will be putting a bed mat in soon. The only things I might haul in it is few pieces of lumber for furniture making, few bags of much etc. Do I really need a stiffener? The only things I don't like is how easily the interior scratches, buckle up seat belt have to be careful you don't it the console buckling or unbuckling the belt. around the door handles if you brush again it with wedding band etc. Two other things is the no intermittent wipers and the POS back up camera. Yes, I've adjusted it a dozen times to different configurations. It's not bright, sharp and definitive like my wife 2016 Subaru Impreza and I've heard the Hondas are sharp as hell. It does shift a lot on the turnpike going up hills in Cruise but they say thats how it runs. On the good side I've averaging over 24MPG all around driving and have 2400 mi on it.
