Lets toss this one out there, this is for the rear mains seal. Since my car is not going to be a daily driver I am thinking of using a silicone rear main seal. Figure it won't harden like rubber so when the car has to sit during the winter I won't have to worry about it leaking down the road. Who has used one & is it worth the extra cost. I still have nightmares from learning to replace a old rope seal back in my early teens & don't want to relive it in the future.