Do you have a pressure washer 
Let the chassis sit in the hot sun to soften the wax and spray export degreaser all over this ... then hit it with a high pressure washer (use hot water if you can). That may remove all of the wax that's causing issues.

this is the crap that was all over the engine bay of one of the cars I'm tinkering with at the moment. It was huge fun to strip too. I reckon it's 50year old brake fluid mixed with oil and dirt.
seeya,
Shane L.
Proper cars--
'92 Range Rover 3.8V8 ... 5spd manual
'85 Series II CX2500 GTi Turbo I :burnrubber:
'63 ID19 x 2 :wheelchair:
'72 DS21 ie 5spd pallas
Modern Junk:
'07 Poogoe 407 HDi 6spd manual :zzz:
'11 Poogoe RCZ HDI 6spd manual
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