i've done it quite a few times with 2mil 8520 AND even the ultramatte 8915 and hardly notice a difference between the two or from using glossy/no lam at all.
this is just for parking lot/misc. signage and vehicle wraps, however, as we just outsource street/highway signage to Tapco... so I haven't needed to look into any sort of "standards" for my printables (yet).