The left quarter window (power) on my '65 300 'vert stopped working. As a result, I bought all new motors (4) from Summit and planned on replacing them all as I used working originals when I restored my car 5 years go. Fortunately, I did not have to remove the regulators to remove the motors. With the windows in the up position, the regulators did not move. Anyway, I had to remove the entire rear interior to get at the motors and trying to clock them so the bolt holes lines up was a royal PITA! The limited space in the interior coupled with 90 degree heat made the job that much more delightful. It took me 6 hours to complete and I woke up sore as hell from the various body contortions to perform the work. Like the title says: NEVER AGAIN! I'm hoping the fronts are easier.