Since it's finally warm again, I've started looking underneath the car and decided to replace all the worn out rubber bits. Looking at the trailing links, both upper and lower in the rear I see that the rubber in them is worn out and cracked. Looking at mazda motorsports site I see they have some options for replacing these. One is a bearing kit to replace the rubber bushings with spherical bearings ($263.40), the other is a urethane bushing kit ($62.60).

I've been having some issues with the rear end making some funny noises, don't know if the old rubber ones are to blame but I'd like to replace them. Has anyone used any of these items? Is it that important? Are they actually one package and I'm confused? I'm just wondering if the fix is worth the money.

Thanks!

Ben.