Looking for aftermarket options for improving the rear suspension of my 2012 Volvo XC70 T6 AWD. I am adding towing to the vehicle so I was looking to improve upon the rear suspension of the car.

Had a conversation with a Volvo Dealership and when I inquired on a tow package addon to the car, they stated that the current setup would be fine for it. I find it hard to believe as I just recently put about 100 pounds of tools in the trunk area and the suspension dropped.

With no load the car it is level. When I had 3 young scouts in the car the car suspension dropped as well. I'm figuring that with almost 170k on the vehicle that the shocks, coil springs might be a bit weak. Was looking to go to a heavy duty setup, but have not been able to find anything yet online.

Then, when I gave Volvo my VIN number they did a look up for my car on the shocks and coil springs for the rear and they come up with part numbers that according to several other Volvo websites should not be a fit for my car.

Does anyone have experience in upgrading their rear suspension on their Volvo XC70 P3 Series? Any help on this is greatly appreciated. If you know of where I should look or can get help on this that would be greatly appreciated as well.
I really want to be able to tow with the vehicle correctly without kill it. Looking at towing a popup camper, a 6 x 10 enclosed travel trailer for my sons Scout Troop and put my bike carrier on when I go biking.

Thanks.