Some are terrible, some are very good.... I think it has to do with how well the guy putting spot welds in place did his job...... I've seen cars that the windshield would move when the door was opened... Scary.... My current Convertible I can raise the LF corner till the tire comes off the ground & at that point the LR & RF are both lifted quite a bit & I can still open & close the drivers door with normal effort & the gaps still look normal... I can also lift it on my rack & open/close both doors... If I were doing a vert these days I'd add US Car Tool sub-frame connectors & I've considered doing it to this car but honestly it doesn't flex much & the bottom of the car is fully painted so I can't justify the work..... Sounds like the car your working on could use the help....