What's best way to clean grime under fender wells?

[Big Z]

The Last time they got a good cleanin, was the last good Rain!...Just like the the rest of the rig! ....Sheeeesh! ..........Just wait for a rainy day, or Find a creek to cross!

[HummBob]

Has anyone used this????:

http://www.hummersolutions.com/produ...ffcef7a20bda97

[tomp]

Can't be all that good of a cleaner if you spray it on after washing & drying.

[Motohead]

I have always cleaned all of my trucks wheelwells with simple green when real dirty. After I spray it with a spray on foam tire shine/cleaner like STP. Shiny as new. Just be careful when spraying the simple green not to get it everywhere.