Water has most probably entered the engine if the engine oil and transmission
fluid looks watered down, milky or beige in colour. If this is the case do not
drive your car, as any damage already done can be compounded. A tow to the
mechanic is the only sensible option.
Similarly, if the air filter shows signs of dampness it will need to be
replaced, along with the oil.
Where water has got inside the headlight and taillight casings the bulbs will
need to be changed.
If you've been unlucky enough to have sustained
flood damage to your car
you will no doubt be interested in looking up your car insurance to see if you
are covered.
Flood damage to cars is generally covered under the most fully
comprehensive car insurance policies. In the main, those with only
"third party, fire and theft" policies will not be covered.