The phrase "opulent cabin" refers to a luxurious and extravagant interior space, typically found in high-end places like hotels, planes, or fancy homes. Full definition
The car's opulent cabin features and chic design could wind up being just what you require from a daily driver. (toyotaofgrapevine.com)
To Audi's credit, compared to the S - Class, the A8's interior has always steered its own course, delivering a combination of dignified, highly technical luxury as opposed to the Mercedes» more ostentatiously opulent cabin. (motoring.com.au)
Well, to mitigate weight increases from a more opulent cabin and an increase in technological features, anyway — the new A8 is up to 95 kg heavier than before, and despite the clever chassis, heavier than the equivalent BMW 7 - series and Mercedes - Benz S - class. (evo.co.uk)