I'd guess the big automakers have a significant investment in their IT department that a MUCH smaller outfit like G&L couldn't hope to afford in their wildest dreams. Love the idea though...
Having worked on IT for a few car dealers, and having helped out G&L on a couple of small IT issues, I can tell you that is very much the case. But G&L has made some small changes in their IT/Web presence world and with the huge growth they are undertaking in production/operations, I imagine it too will catch up at some point.