Thought this might be helpful now as they are popping up...
United Lexia
779 Gnangara Rd,
Lexia
WA 6065
Fuels available:
#E85,
#P100,
#E10, Unleaded 91, & High Flow Diesel
United Armadale
178 South Western Highway,
Armadale
WA 6112
Fuels available:
#E85,
#P100,
#E10, Unleaded 91, & High Flow Diesel
United Osbourne Park
United Osborne Park
479 Scarborough Beach Road
Osborne Park
WA 6017
Fuels available: #E85, #P100, #E10, Unleaded 91, & High Flow Diesel
United Hepburn Heights
4 Walter Padbury Blvd
Padbury
WA 6025
Fuels available: #E85, #P100, #E10, Unleaded 91, & High Flow Diesel
The United Petroleum facebook page has lots of useful information and they regularly announce new locations for their E85.
https://www.facebook.com/unitedpetroleum?ref=br_tf