I believe dome refers to their location (not their shape) if you think of the vehicle’s greenhouse as a dome. Map light are typically located near the rear view mirror, and have a more directed beam.

Yep, was gonna say I already knew all these from Top Gear.

“Dome lights".  So they were pretty much never dome shaped,  but we never had a name for them.  Maybe "map light" ,  but ironically not really a thing we bothered naming.  

Indeed. And a UK gallon isn’t the same as the American gallon, which makes it even harder to compare the MPG on both sides of the pond...

In the U.K. we get it from Americans as when we use imperial (proper imperial, not U.S. Customary Units) use stone in weight.

I’ve heard of swarf, but in manufacturing, not automobiles.

At least they’ve eliminated positive earths.

Nope, that’s a real word. It usually means all the stuff that ends up on the floor of a machine shop. It’s not just metal shavings, it typically means metal shavings and oil, at least that’s how I’ve come to understand it or just come to use it.

Or when they start talking about feet or fingers or ounces or pounds or gallons. It all sounds made up.

Anyone who calls it a dampener is all wet.

damper == shock absorber

For non-native English speakers it’s only more confusing which term belongs to which country. In addition to reading a UK magazine (practical classics), reading American websites (Jalopnik) I also watch Australian videos (Mighty Car Mods on YouTube). Exhaust manifold = headers = extractors. Come on! Make up your mind…

Wait until someone calls it a “dampener”. 

The carriage driver stored his boots in the... trunk, which was called the “boot locker” in the interim. 

Lash is very specific clearance for valves and drive components. Just stick with clearance  

Try being a Canadian. Our speech is a mix of the Queen’s English and terms used by our southern neighbours. I chuckled when I read your chart of terms because I hear both in everyday shop talk up here. Except for spanner... makes sense, sounds odd.

Electrical ground vs. earth, or grounding vs. earthing. There is a certain logic to the translation but it’s still just a bit confusing at first.

I came back to my native Germany from an exchange year in the US (Arkansas of all places) and my English grade dropped from a B+ right down to a barely passed D.

Learn US Spatial Reasoning. Wait until you come to a region named haphazardly after English Geography. will only be made worse because everything around was named Kent/New Kent Sussex, Surry, South Hampton, Isle of Wight, without respect to their original geography. So using proper names were even more confusing and…

If it makes you feel better, after years of Top Gear most of us, especially enthusiasts, would have understood you immediately, and most of the rest would have figured it out from context.