Awesome, for those in IL, it is true, this is what it says about mirrors:
(625 ILCS 5/12‑502) (from Ch. 95 1/2, par. 12‑502)
Sec. 12‑502. Mirrors. Every motor vehicle, operated singly or when towing another vehicle, shall be equipped with a mirror so located as to reflect to the driver a view of the highway for a distance of at least 200 feet to the rear of such motor vehicle.
(Source: P.A. 82‑122.)
and basically if you do have anything covering your rear windows, you do need a side mirror on that side:
(b) Nothing contained in this Section shall prohibit the use of nonreflective, smoked or tinted glass, nonreflective film, perforated window screen or other decorative window application on windows to the rear of the driver's seat, except that any motor vehicle with a window to the rear of the driver's seat treated in this manner shall be equipped with a side mirror on each side of the motor vehicle which are in conformance with Section 12‑502.
...A vehicle equipped with a side mirror on each side of the vehicle which are in conformance with Section 12‑502 will be deemed to be in compliance in the event the rear window of the vehicle is materially obscured.
So as long as you don't have your rear windows tinted, or have anything blocking your view, it's ok to remove the side mirrors
