I did non OEM glass and did the windshield for $135.00 in 45 minutes, it looked exactly like the original with the blue tinted strip on the top. So far no issues it has been about 8 months and no leaks, gasket is fine. Based on that, the four hours seems high for me, also the Toyota glass was quoted to me as about $660 plus. So I figured I could do 4 new ones for that price. Now there should be a follow on discussion on the merits of OEM versus non OEM glass!