You should have done this a few times during the winter months anyway, but now it's imperative, to remove road salt, grit, and grime — all stuff that will damage your car's finish over the long haul.
I often recommend paying a little extra — $100 — this time to year to have you vehicle detailed. That means getting it deep cleaned, inside and out. It's great — you'll feel like you have a new car.
At the least, however, you should get it washed and waxed, or do it yourself, taking additional time to make sure the lower section of the vehicle is especially clean,