I've never seen one before but knew they had to exist. Rare indeed...
https://www.facebook.com/marketplace/item/3997701307153648/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A7a76b95f-9bf9-459e-99d0-4471446f80f1&__tn__=!%3AD
S W E E T ! :001:
And this just showed up on FB another Merc wagon.
https://www.facebook.com/marketplace/item/1231922458349653/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A6bab0513-f10d-43d5-b194-3b901290e78e