I'm certain that the Malibu can be flat-towed with an automatic.
I'm also relatively certain that the KIA Sportage will NOT be able to be flat-towed with an automatic ...if it had a manual transmission, I believe it would be okay to be towed 4-down.
As okcnewbie has suggested, you can check the owner's manual for each to confirm.
eta: I just looked it up, for the 1998 Malibu, it's approved and will state so in section 4-28, page 179 of the owner's manual. For the KIA, I didn't see it addressed but normally, a FWD with manual transmission can usually be towed ...and also, the 2009 KIA is listed in the Motorhome Magazine and the FMCA Dinghy Towing Guides as flat-towable with a manual but not with an automatic. So your only choice among the two is the Malibu.