Hey, cool! I'll give this a try!
It was the green BMW my husband drives that fell off a cliff and got wrecked. (Implying that there is some question raised about which car had the accident?) Actually it might be more natural English to say "my husband drove," since the car is probably no longer driveable. Japanese doesn't seem so concerned with specifying this distinction?
The green BMW my husband drives fell off a cliff and got wrecked. (I assume this is introducing the fact for the first time in Japanese? That is, the listener does not necessarily know any part of this information before this sentence is spoken?)
Now this distinction is interesting. Does #3 imply that the car is *used* for racing, while #4 means only that the car was running at full speed when it went over the cliff?
If so, I might translate as follows:
#3: My husband's green racing BMW went over a cliff and got wrecked. Again, this is a sentence that could start the conversation, I think. Maybe the listener knows nothing about this until now.
#4: The BMW that ran full-speed off a cliff and got wrecked was the green car my husband drives (or used to drive.) Here, I think the Japanese implies that the listener already knows that this accident took place?
It was the BMW that ran full speed over a cliff and got wrecked that was the green car my husband used to drive. (Here, perhaps the listener thought that some OTHER car was my husband's?)
The BMW that ran off a cliff at full speed and was wrecked belonged to the husband who had deserted me. (Here I imagine that we are in a mystery novel or something. Maybe a woman cop goes to investigate a car accident and looks at the car registration and gets a big surprise. If I have understood it, this is the sort of sentence that would end a chapter!)
Please correct my mistakes, anyone!
"Give me a fruitful error any time, full of seeds, bursting with its own corrections. You can keep your sterile truth for yourself." -- Vilfredo Pareto