The side jacking points shouldn't be used at the same time - they are on the balance point of the car. 'Tis a giggle to have sandbags in the footwell to keep the front down, but not exactly safe (surely the point in axle stands in the first place!
If you're talking about using an axle stand after having jacked one side of the car up, I think (with proper padding on the stand) that you could get the jack to one side and the stand to another and still have them both in a suitable place that the chassis wouldn't get damaged....
My point is that if you want the whole back of the car off the deck (as opposed to one side) then, 99% of the time, you're gonna be doing something that requires taking off the tray. How you gonna get the tray off when the jacking bar is on the main rear tray bolts?
See my point?
A bar that would quickly locate to the rear sus mounts, when you took the tray off would be a better bet IMHO. But I'm sure we've had this conversation
