Water up to the dash? That really sucks man.

Along with all the electronics, i'd like to point out the obvious, check/replace the filters, and you might wanna go ahead and change the oil. Water isn't a very good lubricant.

 

I would first remove the plugs to make sure there is no water in the cylinders.(Hydro Lock). Crank it over by hand. Change the oil after this, I'm sure oil seeped into the oil pan. Dry out all COP's, fuse box. After that see if it is throwing any codes.

 

Was the car in your garage in your house by chance? Im wondering if it's possible it would be covered under your homeowners policy.

Then again, youd almost certainly need to have flood insurance.

Follow up - I checked and it doesnt look like cars are typically covered under homeowners.