I recently installed my SPC shim kit & adjustable upper control arms. I got the car aligned and drove it back home - about 10 miles total. The next morning when I left for work the ABS/traction control went nuts - the upper hub bolts (supplied by SPC) that are also the wheel speed sensors had broken off at the head. This had to have happened right when I got home or at some point overnight.
I called SPC Monday morning - this is a known issue. They apparently got a bad batch of bolts. They sent me a new pair of bolts via UPS next day air and I put the car back together yesterday. I did a 50ish mile test drive today with no issues.
I applaud SPC - it took just over 24 hours for them to get me the replacement part. Shipped from Colorado to California! I know it had to cost a few bucks, but they hooked it up. They're known for quality parts and I thought I'd share my story so they'd be known for quality customer service as well.

 

Also - if anyone needs any help on the installation feel free to ask me. There's a couple DIYs here and SPC actually has an install video that shows everything, step-by-step.

 

Quick question please? About the spc a arm. What are the red circle shims for? I'm trying to install this myself but idk what these are

 

I believe they're used behind the new ABS sensor brackets to keep the sensors the correct distance away from the hub.

 

I didn't have any red ones in my kit, but if they look like a large thin washer then they are used to properly position the wheel speed sensor. If the sensor is too close to the hub it will rub - too far and it won't sense the wheel.

If you've already installed the kit and it works then don't worry about it.