I don't want to sound like an alarmist, but I'd be a little leery about driving the car without making sure there's no internal engine damage, and I'll tell you why. Earlier this year I had several cars in the shop with water damaged engines. This is quite common after heavy rains and local flash flooding. One of the cars was a 2004 E320. It appeared to have been one of the lucky ones. It had some water in the air filters and MAF sensor, but that appeared to be it. The parts were replaced, the oil and filter changed, and the car was driven about ten miles. The engine ran fine, was quiet, and no fault codes came back. The car was returned to the owner and that was that. A month later it came back with a connecting rod sticking through the side of the block.

If you've been thinking about replacing the head gasket that you've been putting off for awhile, now may be a good time to do it. That way you can check the piston-to-deck height.

One last thing to add. I've had a handful of cars come back several weeks after we've performed water damage related repairs. The catalytic converters were damaged and set the fault codes for Cat. Innefficient/P0432.