Not true at all, I have a 2014 gt that was "flooded" to the wheels and I have not had a single issue, my brother has one that was flooded higher than the dash and he has put over 70k miles on it and never had one issue, that is after he replaced the motor, and no rust, but needed new seats and carpet
and there is no mold or anything under the dash, even had it tested
That's good your cars are still operable, but that isn't the norm. We have had multiple floods here over the past several years and it ruined a lot of vehicles. I flooded my parents jeep in a creek once and work with a guy who had his late 90's Chevy truck flood. Both are on the road today. My comment was about most newer cars being flooded. There are always exceptions but we have salvage yards full of flood vehicles around here that will never be driven again. Water gets in the dash and it's not going to be a good prognosis.