Does anyone know if I can access the tachometer light bulb through the driver's side speaker. The car is a 1987 300E. If so, what do I feel for ... is the bulb the twist out type that is mounted inside a plastic cap or does it pull straight out?

Smiles.

It's possible, but since you're taking off the speaker you might as well give the cluster a little push. Once out (partially) you can easily change bulb and push it back. If I remember correctly it is a twist off type and should be at the top right between tach and speedo.

Vinamg

If you are going to pull it out, I would replace all of the bulbs while you are in there