the 4 suspension areas and the wheel wells, i can somewhat clean them with a brush & running water. but how do i get all the sand & crap off the undercarriage?? do drive-through car-washes effectively clean the undercarriage?

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Current cars:
2001 MB E55 AMG
2003 Honda S2000
2000 Honda CRV

Gone but not forgotten:
2004 BMW 325i 5sp sport
1999 BMW 540i sport
1997 MB E420
1995 BMW M3 coupe