This might answer your question:
http://www.tintdude.com/atoh.html
PA allows 70% for cars. But here is this site:
http://www.berksweb.com/users/dmv/tint/
And this link that shows for all vehicles:
http://www.cleonapd.com/images/Forms...cle%20Tint.pdf
PA STATE INSPECTION PROCEDURES Section 175.80
(2) Check glazing.
(i) Check glazing and REJECT IF any of the following apply:
(A) Approved safety glazing is not used in every windshield, window or wing.
(B) Any sign, poster or other non-transparent material obstructs, obscures or impairs driver's clear view of highway or any intersecting highway. See Appendix C.
(C) Non-transparent material extends more than 3 inches from lowest exposed portion of rear window, rear side windows or rear wings. See Appendix C.
(D) Motor vehicle has any sign, poster or other non-transparent material on windshield or front side windows, other than officially approved and properly located parking stickers.
(E) Glass is shattered or broken or has any exposed sharp edges.
(F) Windshield is removed.
(G) There are any defects in acute area of windshield,-center of critical area on driver's side of vehicle directly in driver's normal line of vision, 8 _ inches wide and 5 1/2 inches high-or discolorations or hazardous cracks to front, right, left, or rear of driver which would interfere with driver's vision. See Appendix C.
(H) Class etchings, except those used for identification, are on windshield or front side windows.
(I) Glass etchings extend more than 3 inches
Window Tint Law - Chapter 31-23.3
31-23.3-1 Definitions.