Pleased with the symmetry of the last Python Quine, I decided to try for a different kind of symmetry. Here is the first, as far as I know, bytewise palindromic python quine:

#""" d='print \'\\n#\\"\\"\\"\\nd=%s\\nexec d\\n\\"\\"\\"\\nd cexe\\n%s=d\\n\\"\\"\\"#\'%(`d`,\'\'.join([`d`[-x] for x in range(1,len(`d`)+1)]))' exec d """ d cexe '))])1+)`d`(nel,1(egnar ni x rof ]x-[`d`[(nioj.'\'\,`d`(%'\#"\\"\\"\\n\\d=s%n\\exec dn\\"\\"\\"\\n\\d cexen\\s%=dn\\"\\"\\"\\#n\\'\ tnirp'=d """#

Note: it starts with a blank line, and has long lines that will wrap above. Here's a unreadably small version that will cut & paste correctly:

#""" d='print \'\\n#\\"\\"\\"\\nd=%s\\nexec d\\n\\"\\"\\"\\nd cexe\\n%s=d\\n\\"\\"\\"#\'%(`d`,\'\'.join([`d`[-x] for x in range(1,len(`d`)+1)]))' exec d """ d cexe '))])1+)`d`(nel,1(egnar ni x rof ]x-[`d`[(nioj.'\'\,`d`(%'\#"\\"\\"\\n\\d=s%n\\exec dn\\"\\"\\"\\n\\d cexen\\s%=dn\\"\\"\\"\\#n\\'\ tnirp'=d """#