-- Last Updated: Jan-17-13 11:30 AM EST --
I use factory x-bars with Malone Autoloaders ( J-type racks), routinely transport two boats
Even though I had no problems with factory x-bars many folks would advise to purchase cross-bars from Thule or Yakima. Some folks that accessories stay put better on the rectangular bars ( Thule) better than on round ( Yakima)
Edit - mine is 2006 Impreza Wagon with tow package. I use the tow bar for rear tie downs, there are two holes in the metal bracket inside the lower radiator grill scoop that I use for front tie downs.