Looks a little cramped.

Can the train passenger RMotD fit into this tiny coach?

An excellent carriage and a great source for 1x2 Trans Clear bricks. Had a couple at the time, plus some 124-1s and 125-1s.

@MCLegoboy said:
"Looks a little cramped."

Not if you ride on top.

@Maxbricks14 said:
"Can the train passenger RMotD fit into this tiny coach?"

Sure. Looks like an extra roomy coffin. With windows.

You’ve got to shell out for first class if you want things like “headroom”

@MCLegoboy said:
"Looks a little cramped."
Actually, there would be plenty of room inside, since it's built on a 6x16 plate. Headroom, at least for a minifig sitting down, would be plenty as well.
The problem is that LEGO either didn't have or decided not to use 1x4 plates in yellow for the decorative stripe. Weird, because it doesn't really look good with 2x4s.

@AustinPowers said:
" @MCLegoboy said:
"Looks a little cramped."
Actually, there would be plenty of room inside, since it's built on a 6x16 plate. Headroom, at least for a minifig sitting down, would be plenty as well.
The problem is that LEGO either didn't have or decided not to use 1x4 plates in yellow for the decorative stripe. Weird, because it doesn't really look good with 2x4s."

A bald minifig is three bricks two plates tall when seated. Sitting on the lower grey layer, the stud on the minifig’s head would be plugged into the upper grey layer on this model, _or_ the minifig would have to be reclined far enough to prevent that. In cases where hair or headgear is involved, reclining would be the only option. Of course, we know from the airline industry how popular reclining seats are with the passengers seated immediately behind, so perhaps it’s appropriate that this thing is shaped like a coffin. Saves time on cleanup.

It doesn't matter if a minifig fits or not.....after all, how are they supposed to get inside?

Luckily back in 1969 they still had a few years to invent doors before the first (unarmed) minifigs appeared.

@TheOtherMike said:
"How many people saw "25 Trains sets produced that year." and started sobbing?"

*weeps quietly*

@PurpleDave said:
" @MCLegoboy said:
"Looks a little cramped."

Not if you ride on top.

@Maxbricks14 said:
"Can the train passenger RMotD fit into this tiny coach?"

Sure. Looks like an extra roomy coffin. With windows."

Like for royalty.

@WizardOfOss said:
"It doesn't matter if a minifig fits or not.....after all, how are they supposed to get inside?"

Perhaps you've not heard that TLG landed the Star Trek license? Transporters. Or that they have the HP license? Magic. Plus there are Superheroes like the Flash and Martian Manhunter who can simply phase through matter.

@PurpleDave said:
" @WizardOfOss said:
"It doesn't matter if a minifig fits or not.....after all, how are they supposed to get inside?"

Perhaps you've not heard that TLG landed the Star Trek license? Transporters. Or that they have the HP license? Magic. Plus there are Superheroes like the Flash and Martian Manhunter who can simply phase through matter."

Not to mention Ant-Man, who can be as small as he wants. Or Green Lantern, who can say "Screw it" and will his own coach into existence. Dr. Strange also has magic. And I know Lego doesn't have the Doctor Who license anymore, but maybe the coach uses Time Lord technology, and thus is bigger on the inside.