Have a 89 328------should the extenders actually snap down onto the plug?? Pulled one off to look at tonight and there was green corrosion on both ends--pulled the other 7--yikes!!! Total 5 out of 8 were green at the ends. 3 looked like they were brand new. Of the 3 new looking ones -2 had a different clip design where they snap to the plug. The clip was much bigger looking. Those 2 snapped back on the plug no problem-nice, tight and secure feeling. The other newer looking one will not actually snap on the tip of the plug. Tryed different plugs and no go. Will this hurt performance?? Ordered 5 new ones from Ricabi,but they are the ones with the small looking clips. Can't imagine it will hurt too bad since actually unbeknowst to me 6 out of 8 were never snapped on.