(CNN) — Luxury carmakers have always been willing to pimp our ride -- for a price.
From bespoke wood veneering, to shimmering hamper sets, opulent accessories are now the growth category in the luxury car industry.
It's helping to double and, in some cases, triple the basic price tag for top-end vehicles.
When you consider that Bentley's latest luxury SUV, the Bentayga, has a base price of $231,825 -- but fully loaded can cost somewhere north of $750,000 -- then you know it's big business.
So luxury auto designers are now turning their attention to the vehicles' trunks to capitalize on the trend.
They're pulling together high-end luxury luggage collections to fit snugly into what was once an unprofitable void.
Rolls-Royce spent months of intensive research on the design of its hand-tailored luggage collection.
For a mere $45,854, customers can fill the trunk of their new $320,000 Rolls-Royce Wraith.
That'll buy them six-piece collection that includes two large Grand Tourer valises, three Long Weekender bags and one garment carrier.
Rolls-Royce Bespoke Designer Michael Bryden tells CNN the collection is aimed at people with so much money, they rarely handle their own bags.
"We spent some time at a high-end hotel in London speaking with their head butlers to get an understanding of how customers interact with their luggage," he says.
But while the concierge might be left to grapple with the largest carbon fiber case, the Grand Tourer, customers will still need bags they carry themselves, adds Bryden.
"One very interesting point that came out of our research was that customers will travel with highly valuable items such as timepieces, jewelry and they might want to carry them themselves so as not to let them out of their sight."
Don't forget the car! That custom luggage fits perfectly in the trunk of the Rolls-Royce Wraith, appreciated here by New York socialite Olivia Palermo.
Bryden says the team spent almost as much time on the handles as it did on other components in the luggage collection.
"The handles come together to create quite a large surface area so that you can grab hold of it -- it spreads the weight so that it doesn't dig into the customer's hand," he says.
To that end, the bag has the same lines of invisible stitching that can be found on the steering wheel of the new Rolls-Royce Wraith.
It also engineered the handles for lefties as well as righties.
"Whether you're a left-hander or a right hander, the feel is exactly the same," says Bryden.
Other touches include the same self-righting wheel centers -- with the world-renowned double R marque on them -- that can be found on the cars.
"When we got one of the first luggage prototypes back, the RR was spinning around and we immediately thought 'that just doesn't look right'," Bryden adds.
"We spent a great deal of time taking the mechanism that was on the Wraith itself and scaling that down to make it work on a luggage piece. It's really quite fantastic."
The Long Weekender bags also magnetically dock in the trunk to stop them rattling around when the Wraith is on the move.
Bentley's bespoke hamper keeps your champagne chilled -- for $40,000.
Rolls Royce isn't the only luxury car maker muscling into luggage market.
Porsche has produced its own carbon fiber and leather luggage lines, albeit without quite the withering price tags.
Porsche's signature luggage collection for the Spyder 918 -- with the kind of German engineering that allows for the same satisfying "clunk" on suitcases as on car doors -- retails for just under $20,000.
Bentley this year also produced its own opulent trunk offering in the shape of the Linley Mulliner hamper designed to fit perfectly into the back of its first off-roader, the Bentayga SUV.
Aimed at the polo and picnic set, the hamper features fine china crockery, silver cutlery and crystal glass in the first compartment.
There's an illuminated champagne cooler in the second compartment, and a space for food, dry goods and a Mulliner cashmere picnic rug in the third.
Even here the Bentley branding is meticulous.
Each champagne glass base is created to look like a five-spoke Bentley wheel and its bottle stoppers carry the winged "flying B" Bentley logo.
While for many it may look like a costly champagne cooler (at around $40,000 it retails for about the same as an average new family sedan), Bentley brand manager Adam Hannaford says more than 100 clients had already ordered the hamper.
"The amount of interest that we've had is staggering."