The Bentley Mulsanne Speed is an impressive automobile. With a price tag just shy of $400,000, including options, this shouldn't really be a surprise to anyone. After all, this is Bentley's flagship model.Recently, Business Insider spent a weekend with the Mulsanne Speed. Behind the wheela position normally inhabited by a chauffeurwe found the Mulsanne to be a harmonious blend of luxury yacht, English cottage, and Germanic muscle car.Powered by colossal 530-horsepower, 6.75-liter, twin-turbocharged V8 engine, the Mulsanne Speed is perfectly capable of spirited driving and can reportedlyhit a top speed of 190 mph. With a dump-truck-like 811 ft-lbs of torque on tap, the18-foot-longBritish limotakes just 4.8 seconds to get its 6,00o lbs. of mass to 60 mph.However, no matter how sporty Bentley try to make the Mulsanne, it will never be as athletic as its little brother Flying Spur which we tested last year.Butthe Mulsanne Speed is still most happy when it's ferrying aroundwell-heeled passengers.The place to be is seatedbetween the Bentley's vault-likerear doors, which close with a very satisfying thud.And boy! What a rear cabin it is! And it costs $43,300, fully equipped. In fact, on its own, the Mulsanne Speed's back seat is pricier than dozens of brand-new, rather hot cars on the market today.So weput together a list of 25 cars that are actually cheaper than the Bentley Mulsanne Speed's rear cabin.SEE ALSO:Porsche's new $100-million US headquarters is like Disneyland for car loversAt $28,760, the "Entertainment Specification" equips the Mulsanne Speed with electric iPad picnic tables, a rear seat entertainment system, Wi-Fi, and a "Naim for Bentley" premium sound system.For another $3,750, Bentley will install ventilated leather seats with a massaging function.To top it all off, Mulsanne Speeds can be optioned with a "refrigerated bottle cooler with frosted glass and bespoke crystal champagne flutes" for a whopping $10,970.See the rest of the story at Business Insider NOW WATCH: Tom Hardy makes a crazy transformation playing identical twins in this new gangster movie Click here to read full news..