Tamaroak writes:

Is there anyone out there with a chemistry background with an opinion on
this?

Comes now http://www.coleparmer.com/techinfo/ChemComp.asp
and witnesseth:

The Material Selected Polycarbonate
Interacting with the Chemical Diesel Fuel
Has a Compatibility Level of A-Excellent

I would suggest you put samples (including thin shavings) of your plastic
in a capped Mason jar of diesel fuel starting now, as a test. Have a look
in another few weeks or months.

Polycarbonate is the usual item for machine tool safety shields, where it
is constantly sprayed with hot hydrocarbon oils.

Seems like I've heard something about oils embrittling polycarbonate.