So I just put new wheels and tires on my 850 (18x7.5's vs. stock 15x6.5's). The issue is that when I have passengers in the back seat, the added weight causes the rear wheels to rub on the back of the wheel wells. I looked up some overload springs on the IPD website that can increase the ride height up to 1/2 inch and add an extra 300lbs. to your load capacity. Is that my best choice?
I have also heard that they make station wagon springs stiffer (because of the added weight) and may be able to find some that could fit at the junk yard. If anyone has any suggestions for how to protect my new investment, it would be most appreciated. Thanks in advance.

 

Whatever rear springs that you decide to use...

Just make sure that they are progressive rate. The top and bottom loops of springs should be wound a little differently than in the middle. This enables the spring to start out a little bit soft and firm up quite a bit during hard turns.

You may be onto something about station wagon springs. Check with parts desk at your dealer. Maybe they have some more info about spring rates.