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.

You can try the wagon springs I haven't heard of them being stiffer yet.

Me I would go with the IPD kit and make it really stiff to save the tires.

Thanks, i think that is what I will end up doing. I think IPD even may have some on closeout right now.

IPD's overload springs.