So basically you have wet carpets and the electrics on the seat are wet.
Water won't hurt the engine if it isn't running and it doesn't get high enough to run into the intake manifold. About dash high---
Premature rust in the exaust, maybe. Water is one of the byproducts of combustion so it is usually wet inside on short drives anyway.
Wheel bearings needing replaced all around are a possibility.
Do the 3's have computers in the sills? If not then you can probably drive it away when the water goes down.
Check the dipstick first though.
One of the Roadfly 8 owners had water a bit deeper than that in his 8 in New Orleans. Replaced one of the computers in the sill and dried it out. He is now running around Houston in it, none the worse for wear
His 7 was another story--9 feet of water where it was.