If you don't find the side screws, run a tiny flat screwdriver tip gently along each edge of the panel from front of dash towards the firewall -- note where it binds. There's a large plastic "screw" that turns one-half turn and pulls straight out. THEN the panel will drop.

I think. It's raining or I'd go check. That's the deal for sure on the w123, and I'm pretty sure it's the same on the w126, allowing for the addition of the carpeted modules that have the door vent hoses in 'em.

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Anthracite 1980 300D -- 64k original miles with a new engine, on the road again!
Silver 300D -- second owner, Sunny's old baby, Ilse, 210 miles,
Having to thin the herd….
Silver 1983 300SD -- second owner, 325k miles
Gold 1981 300D -- well-traveled, solid little car
Beige 1984 300D -- 292k miles, grease machine, parting out
Seafoam green 1981 300SD -- 250k, windshield frame damage
too many assorted w123 & w126 cars, parts cars, and extras