AutoNation has a notion it's akin to Tiffany

Is AutoNation more like Tiffany & Co. or Penske Automotive?

Tiffany, says AutoNation's compensation committee.

That committee reviews executive pay at the nation's largest dealership group, making sure it's competitive with what's offered by AutoNation's peers. To do so, it first has to decide who those peers are. The company's proxy says the committee decided that AutoNation's "peer group" is made up of retailers, but only one vehicle retailer: used-car specialist CarMax.

In addition to Tiffany, the list includes Nordstrom, Staples and The Gap -- but no other dealership groups.

That's not the norm among publicly traded dealership groups. At Lithia, Sonic and Asbury, the peer groups include the other public auto retailers. Group 1 and Penske haven't released their 2014 proxies yet, but have included other public dealership groups in their peer groups in the past.

AutoNation, Asbury, Lithia and Sonic also include in their peer groups several auto parts retailers, such as AutoZone and O'Reilly Auto Parts. Sonic, for example, includes Dollar Tree, Dollar General and Family Dollar Stores.

AutoNation isn't alone in comparing itself to Tiffany. Asbury also includes Tiffany in its peer group. But Asbury also compares itself to Tractor Supply Co.