I'm at a bit of a loss here, because my familiarity is with the W126, and an older 116 I had, but if I understand your situation, the bolts you need to remove are behind the inner door-skin, 1/8" or so, so no room to manouver an end wrench. But if the bolts are facing the doorskin, not sideways, how about taking a 3/4" hole saw and drilling out enough to get a socket on them? This method is actually the shop manual way to get at the regulator bolts on a 126 (or was that a 116? Front or rear door? I forget).

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1986 560SL
2002 Toyota Camry
1993 Lexus