pulling/slight shimmy..questions

[AKawd]

heres the rundown...

a few weeks ago we got 20" BOSS wheels installed. the wheels are 9" which is wider then the stock wheels im aware.

now, our roads can be very bad..with large frost heaves, huge ruts somtime 6" deep, uneven serices...ect not that great.

grandma has been complaining that it shimmys alittle left/right and pulls left/right alittle.

I have driven the car a good 200 miles atleast around town, highway..about every situation possible and it seems fine to me..no real pulling or shimmy.

after i got this imformation from her, i took it for another drive...at first i thought it was pulling. untill it did it both ways sooo what does this mean?

i think that the large ruts, combined with uneven road serfaces make it seem like a very slight shimmy/pull but since it does it both left and right and goes if you move out of the ruts i have to say its not the car or wheels/tires fault for this sensation. i'd pretty much say this is a given with wider/lower profile tires..correct?

so am i correct in saying its not the car/wheels fault? the car has 11k miles on it but grandma is wondering if it needs an alignment? and the possible tie rod issue worried me also..even though its under warrenty.

so bottom line, could this be a car issue or road issue?

sorry to be so long, thanks for any information.

[onthelo]

usually a shimmy or not straight steering can be an easy fix as an alingmnet maybe even an unbalanced wheel also Id check those things first before checking the tie rods and such and than the wheels them selves.