I had this happen several times on my 83D. I even had to help a lady in a parking lot get her MB trunk open.. she said it was aggravating at times. I have no sure fire formula but here is what I did to get my trunk lid open--- Insert key (horiz. position); turn left (counter clockwise) putting the position to vertical; with key still inserted, push button in; if trunk does not "pop" open, continue hold key/button in and with your other hand lift gently on the trunk lid. If this doesn't do the trick, then insert key again (horiz.) then push in and then turn counterclockwise, try lid; if failed, then continue to hold key pushed in.. in vertical position, release pressure to allow button and key to come to "out" position, then push in again on key and button and try lifting trunk lid with other hand. (boy, if you can understand these instructions, you're a genius) I had to try the various options that I described and then just "use the force, Luke" to "feel the moment" between key, button, and hand. Mine always opened though.. never had anything done to fix it.. just some days it opened normaly and others it was "abnormal". Good Luck.

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Nello Tare

1982 300D (266,001 mi.) looking and running great

Previously owned:
1976 450 SLC
1983 300D
1976 300D
also
1982 Jaguar XJ6 (loved, but gone)