They are pretty stout vehicles in general but the only things i've heard of are the roof braces on like 148+ systems or ones that have huge amounts of flex.
One was built down at the shop... 4 15" Ascendant Chos in a ported clamshell behind the back seats. 2 Hifonics Brutus 2000s. Will Bassrace a 149.9.
Dont have any finished pics, but its definately done and it looks sick. Alot of work went into that box. Ports actually went on the sides of the clamshell. Ill try to find pics of it. If I cant find any ill just take pics next time I see the kid.