Originally Posted by ABMW

Soak a sponge in vinegar, set the sponge on the spot or tape it using blue making tape (painter's tape) and then clay the car using a high quality lubricant. DO NOT USE LIME AWAY! That has the potential to destroy your clear coat and the paint beneath.

If you're not comfortable with the above, take it to a professional detailer who will charge you no more than $200.00 to clay and wax your entire car. It's worth it, as the products you'd need to do the job properly will cost you $50.00 anyway.