I've tried 3 different spring sets on my car and the left/rear is always 0.5 - 0.75 inches lower than the right.
What could cause this? Can the spacers wear out?

Thanks.

 

The driver weight will always make the car sag in the left corner.

Thats why I went with Tein Coilovers so you can have 4 corner independent adjustment.

 

+1 Tein rocks!

 

Any way to correct this without going to adjustables??

 

Select a passenger whose weight balances the situation. Honey you must gain 30 pounds?

Unfortunately the world standard for a drivers weight is 150 pounds used to design cars.

Many people are confused by the un mounted stiffness of springs [forgetting the angle and offset distance from the hub].

Mounted stiffness generally means the real world stifness is 140-180 lbs per inch on the front.