my dad has owned 3 4th gens.all with t-tops.none of them leaked.the chassic on the 4th gen is much stronger then the previous cars.prime example.my dad had a 20th anniversary TA with 10k miles on it.theres this lop sided hill near my house that levels off suddenly.when cresting the top u could feel the 20th flex with the road.with the 4th gen the rear left tire comes of the ground and when it comes back it squeels tire for a second.plus in the crash test the front rear and side impact it got no less then 4 stars.i think it was 5 upfront and in the back and 4 in the sides.my dad is a GM Tech and thats wat he tells me.but like ne thing else if u dont take car of ur car then yes the t’s will most certainly leak.