Take, for example, today's test car, the 2007 Mercedes-Benz GL450.
It's not as if the world really needed another big SUV, but Mercedes-Benz certainly needed to produce one. The loyal owners of other Benz models were looking elsewhere when they went in search of heft and hauteur.
Even owners of the company's M-Class cars were leaving the brand to pay lots of money for someone else's luxury behemoth SUV.
Porsche, known for its sports cars, drove down this road in 2002 and its Cayenne line, arguably, saved the company from takeover by virtually doubling Porsche's overall sales.
So what's the GL-Class have to offer that will keep Mercedes owners from leaving the family?
Luxury, power, smoothness, and capability -- at a price that ranges from a base level of around $56,000 to about $70,000.
You can put as many as seven people into the GL450, which is the proper way to use an SUV as opposed to the yahoos who commute to work by themselves in big rigs every day.
The GL450 can tow up to 7,500 pounds, enough to handle a decent sized boat or horse trailer. Again, it's the kind of use SUVs were intended for, and Mercedes makes it easy.
You can get a drive train that features off-road capacity such as a two-speed transfer case, locking center, and rear differentials, and an advanced air suspension system that can provide about 12 inches of ground clearance to avoid rocks, or double that if you have to travel through deep water.
Yet, with a 200.3-inch overall length and a weight of more than 2 1/2 tons, who would really consider doing heavy off-roading in this rig?
The car is at its best with a base drive train that will get it to the ski lodge, the trout stream, the deer stand, or the Hamptons or Nantucket.
Of course, even on smooth roads, it's all about moving ahead, and that's where the GL450 shows off its best features.
The 4.6-liter V-8 engine puts at your disposal 335 horsepower and 339 lb.-ft. of torque -- that's more horsepower and torque than almost any driver will ever need or should use.
And best of all, the power is transmitted to what is becoming my favorite non race track transmission on the planet, a seven-speed automatic that says, simply, "Don't worry, I'll get you there and you won't hear a thing from me."
Mercedes lumps critical safety features as standard fare into the GL450, including traction control, adaptive front air bags, seat mounted side air bags for the first two rows, and window curtain bags in all three rows.
Leather, bird's-eye maple, and heated power front seats help define the interior elegance, while the outside looks like your basic big SUV.
If you want to spend some extra money (and Mercedes is happy to accommodate), options include Bi-Xenon headlamps, corner "seeing" fog lamps, an upgraded Harman Kardon sound system with 11 speakers, three-zone air conditioning, a power tailgate, heated second-row seats, and a navigation system.
Do this dance and the base car price can quickly escalate to around $70,000, as did the base car we tested.
But what's a few thousand dollars more when you're already traveling in the high-end lane?
Royal Ford can be reached at firstname.lastname@example.org.