Mr. Kalch,
I am sorry if we didn't get your window fully clean after installation.
While I am not sure of who used alcohol and a dirty rag to clean your windshield, I do know that we typically use only fresh paper towels, and Sprayway glass cleaner, which we find to be the best cleaner available during the installation and clean up process.
I hope that you will consider our services in the future!
Thank you for your business!