these look like AMRAC or Rokars to me

http://cgi.ebay.com/3-Rare-Cox-Porsche-934-HO-Slot-Cars-Mint_W0QQitemZ6005007403QQcategoryZ2619QQrdZ1QQcmd ZViewItem

According to Hoslotcars.com (http://www.hoslotcars.com/cgi-bin/searchsl?index=0&from=searchsl&func=search&txt=cox&what=0&format=0&user=&password=&num=100&sort1=-1&sort2=-1&sort3=-1&sort4=-1&sort5=-1&sort6=-1&sort7=-1&sort8=-1&sort9=-1)

it exists some...
But they really look like good ol' Amrac.....


The same seller was selling last week the one in front (Yellow Orange with number 4) and it was noted as an Amrac rare one (i know because I was following the auction....)

Of course they look like Amrac as Amrac bought the HO slotcar Line from Cox, then the line went to Rokar and finally to Life-Like. Any Darda cars or Galoob cars/sets that you see were just Private Label stuff made my Rokar for them.

I have a few of the Cox stamped chassis, they are identical to the Amrac chassis with the exception that Some have a different colored Armature.
The newer Amrac Armatures seem to be faster, so that was probably an early upgrade.

I also have the Blue Datsun and Yellow Porsche both with the Cox chassis.

Funny thing is, Amrac and Rokar were always looked down on by the "The Only Good Slotcar is an Aurora" snobs for years and now people are going bonkers for some of the models.
I used to buy every Datsun I saw in the $10 boxes at shows and am now very glad that I did it then as those days are long gone.

Thanks,
Keith

They may be legit. The high bidder's feedback rating is 703, which at first glance tells me he's a collector or a seller. I checked another of his auctions, 3 Datsuns, and there's a shot of the chassis, and there's a Cox logo on them. I've never seen those color schemes before.