Ramps for Pressure Wash?

[svxthc]

Do you guys recommend I buy some 40$ ramps for my car to pressure wash the undercarriage? Is it safe and effective to do it without the ramps with the svx being so low to the ground? I wonder if they will make a difference at all with a straight vertical shot of about a foot from straight under the car or if I should just angle the shot under the grounded car? Damn salty winters.