Getting concrete of a car

[Ninjaboy]

My dads car has got concrete on all up the passenger side from when the bloody water company dug up half the road. Any idea's how to get it off? He didn't notice it straight away so its dry and is a royal pain to get off.

[Beyond Rational]

Get onto water company, get car into body shop.

[PGM]

Diesel gets it off OK.