titan tailgate failure 2008

im new to the titan forum, and let me first say thankyou for all the info you have shared on here. i have a tailgate question. i have just purchased a 2008 kingcab longbox se 4x4, and the previous owner had the tailgate buckle in half while loading his 4wheeler in the truck going up the ramps. when i talked to the dealer i was told that these tailgates are very cheeply made, and cant withstand the 900lbs of the wheeler and plus add the weight of the rider. he said toyota also had this problem and rectified it back in 2005. the answer i was givin to fix this is to leave a sheet of plywood on the floor and slide it out to the end of the tailgate b4 loading.. i havent picked the truck up yet from the dealer yet, as im waiting for the tailgate and the rear bumper to come in(when the tailgate failed, wheeler and rider rolled over tweeking the bumper and dented the bottom corner of the box) and then it has to be painted to match the truck. any 1 else have this issue with the rear gate?it literally caved in upward like a mountain peak for a lack of a better way to describe it. im guessing at that point it allowed the bottom hinges to come off and he went *** over tea kettle.
also, was just curious how many miles people have on there engines. i have had several toyota trucks and had over 250,000 miles on them and the only issue was making sure you kept the timing chain or belt, according to what year it was, changed when it should be. otherwise no issues. how about these titans? anything to watch for or problems? i, as is the previous owner, am an avid outdoorsman and will have a 900lb wheeler in the back of this 80% of the time also so i really need to find out if an aftermarket tailgate would be stronger than an oem replacement(not sure what they are sending). ive never had a problem with any other truck doing this,cant believe i should have to carry extra stuff so i can load a wheeler. thanks for any info, as i paid for the truck a week ago, and havent even really drove it yet. 50,000 miles on it, paid 16 grand for it. sound like a decent deal? thats a little less than bluebook showed(about 2500 less)