20" Wheels = Shaky Steering??

[FeelGoodUnInc]

My 2nd post on these 20" staggered wheels I apologize..I just got these intalled today with the toyo tires, and also these wheels are replica's not genuine from a company called AFS wheels with very good reputation from what I hear

Anyways I'm not sure if it's normal but during slow speeds the steering wheel becomes very noticeably shaky back and forth..not out of control but just ever so slightly left and right real fast..I checked the wheels and they don't seem to be out of round but it's hard to really say...for about 20-30 miles on the freeway at speeds of 5-20 mph it was shaky the whole way and then when i had some freedom it went away but came back slightly every once in awhile...any suggestions would greatly be appreciated..paid so much and now these issues arise =(