We finally replaced our windshield after 5 years and a severe crack this year + 3 major rock hits from I495.
I ended up using Safelite if that matters through insurance.
The windshield is noticeably distorted when you move your head up or down a bit. Is this normal for aftermarket glass? Or just a bad windshield?
No it isn’t normal. I’d take it up with Safelite.
No, it’s not normal. A replacement windshield should be as clear as an original windshield.
If you have problems, take it back.
How normal depends on how closely you are looking. All glass will have some distortion, but you should not easily notice any during normal driving. I have had new cars with slight distortion.
Anything over minor is too much and I believe most any glass supplier would take care of that for you. In my personal experience your vender is on the the better ones in an industry that appears to have few problems.
Windshield distortion was very common in the '60’s to the early '80’s. Then quality controls improved and designers worked to reduce the curves and angles in windshields. Today distortion is very rare, and in this case likely a defective windshield.
I would contact the glass contractor and if necessary your insurance company that paid the bill. The only solution is to remove it and install another windshield, or you learn to live with it. I used the “live with it” option for many years on a number of cars. Eventually you just seem to get used to the distortion. Today you shouldn’t have to live with it and deserve a better result.