Brand new set of switchbacks for me too. Wow these things are bright, they add a lot of close visibility to the sides. You can see the glow on the road. I got this set: iJDMTOY 27-SMD-5050 Bi-Color White/Amber
I have not put on load resistors yet. The only issue is they hyper blink and throw a code. The ones with built in resistors look good, but you sacrifice led space for the heatsinks.Did you have to use load resistors with them ?
Also I was looking at some bulbs on eBay that state they have built-in load resistors...but if they actually work to correct the issue...is another guess.