Wheel well grime removal

[JOPRIMO]

(Did a search but came up empty)

After I purchased my 95 last fall, I noticed some buildup of what appears to be road grime inside my wheel wells. Using a flat-head screw driver I attempted to "scrape" some off. That stuff is thick and simple green didn't even phase it.

Any suggestions on another safe removal tool/process? Would it be better to remove the entire plastic wheel well for the cleaning?

 

[lemansnsx]

Here is what has worked for me:

remove wheel well liner
cover inside of liner with heavy paper towels - the blue kind from the auto parts store.
saturate paper towels with bug & tar remover or plain kerosene. keep wet.
let sit for a while then wipe away the residue. Rinse with soapy water.