Near new Elantra wanders at higher speeds

Didn't notice when test driving but Elantra Limited steering wanders left to right, right to left continually. Requires constant steering attention.
Dealer checked toe and it was out. Made no difference. Also checked car's computer and told me the computer was set up for the "other" engine. Been 10 days since was advised factory service adviser would get back to me as to what they will do about it.
Any alignment person/persons out there to help out? Suspect the castor is needing adjustment and wondering if it is adjustable on this vehicle.
Any advice or help certainly appreciated. Also advice when dealing with Hyundai about technical problems such as this.

Have learned that the out of lane warning equipment is the cause of "wandering". It watches all the white markings plus cracks and patches causing the unit to try to correct by steering in several directions one after the other. It can't be set to warn and not steer.
Dealership told me to turn it off.