For the first decade of Saturn’s existence, “no-haggle pricing”–the sticker price is the price everyone pays–made sense. It made Saturn dealers very easy to work with, and the brand’s reputation benefited. But today, despite an all-new product line-up, Saturn is falling short of its sales goals. The products are solid. The problem: no-haggle pricing.

Why did no haggle pricing work before, but not today? Two reasons: discounts have grown large everywhere else, and Saturn’s products now have close relatives at other GM divisions.

Consider the Aura and the Outlook using TrueDelta’s vehicle price comparison tool. (These model names should be ALL CAPS, but that gets obnoxious.) Despite all of the PR about supposed German origins, the Saturn Aura sedan is most closely related to the Pontiac G6 and Chevrolet’s 2008 Malibu. Compared to the Pontiac G6 GXP with a few options to bring it up to the Aura XR’s standard equipment level, the Saturn lists for about $100 less. Sounds quite good considering the fancier exterior and more upscale interior of the Aura. But the rebate (which only became part of the Saturn way in recent years) is currently $500 higher on the Pontiac, and the gap tends to be at least this large year round. Still, the Saturn would be just $400 more if both sold at list, a very fair price for the extra bling.

But of course both don’t sell at list. Instead, the G6 can probably be bought for around invoice. Let’s assume $250 over invoice, to be safe. At this price, the Pontiac G6 GXP will cost about $1,500 less than an Aura XR. Even adjusting for the Aura’s additional features, the gap remains a sizable $1,200. And the upcoming new Malibu will be cheaper still.

The Saturn Outlook crossover faces an even tougher battle against the GMC Acadia, since while the G6 is positioned below the Aura, the Acadia is positioned above the Outlook. The Acadia SLE lists for $1,500 more than the Outlook XE. But in this case only the Saturn has a rebate, for $500. So the gap at list price is $2,000.

So why is the GMC far outselling the Saturn? Well, partly because there are more GMC dealers than Saturn dealers. But the reason many buyers have given me (especially back when neither had a rebate) is price. The GMC might start out $2,000 higher, but it includes about $700 more in standard equipment, and at $500 over invoice (it’s a stronger seller than the G6) it’ll cost about the same as the Saturn. More stuff, higher status brand, same price (even with the rebate on the Saturn). The outcome is predictable.

GM has tried to compensate for Saturn’s no-haggle policy by reducing the dealer margins on Saturns and making the list prices a bit lower than they’d otherwise be. But with today’s large discounts, the pricing adjustment isn’t large enough.

One solution would be to reduce the prices on Saturns, so that at list they’d be more competitive with both their siblings and competitors from outside GM. But this requires knowing in advance how large the discounts will be on competing vehicles. Which isn’t easy to do–hence the $500 rebate on the recently introduced 2008 Outlook.

A simpler solution might be to abandon no-haggle pricing. It worked before the era of huge rebates and discounts, back when Saturn’s products were truly unique. But today, it’s hurting them more than it’s helping. Cars and SUVs that seem attractively priced at sticker don’t seem so attractively priced when out-the-door prices are compared.