As the discussion poster said, I am now starting to see the same problem. Accelerating in 5th gear was my first sign on the highway. Going about 55 then pushing down the pedal the engine revved up and the the clutch kicked in a moment later. 2004 GTS 5 speed. Clutch always grabbed, no issues switching gears (although 1st to 2nd cold was tight and second can grind if not careful). Owned the car 8 years now with 154k on it currently. (Mom Bought it new and now I own it) Got the manual transmission fluid changed at Valvoline on a Friday and didn't hit the highway until Monday. I do about 110 miles a day now that I am no longer working from home for the past 4 years. I have been commuting for 3 months now. Only run 93 in it and constantly run Lucas and Techron though the gas tank. Today I noticed the slip..It's a Monday after the manual transmission fluid change which I first did back in 2018 when the car had 126k on it. They put in their Valvoline Syncromesh on their recommendation vs conventional 75/90. Fluid was still clear when I changed it as I asked them to see it. Went back to them tonight and had them put back in the standard 75/90 as this girl is use to that.. not a full synthetic manual transmission fliud.. which is what this girl is used to. Took it for a ride and tried to replicate the issue, and to no surprise I was able to replicate the issue in every gear but you had to get on it. Thought is was the new fluid they put in. Clutch has not been acting any differently before then as I never beat on it or spin the tires (Grandpa here lol). Be interesting to see what the new clutch does as the clutch pedal is tight as always and it still grabs like I know it to. Getting a quote for a new clutch tomorrow. After reading this forum it seems I have to replace it which is nice to know what may be causing it. Thanks guys for your hard work so I dont have to pay a shop to troubleshoot what may be simply a clutch. Just spent 3k into a brand new brake system and general maintenance as the rotors have been changed out like 3 times and still warp...Went carquest this time as slotted and drilled was way too expensive but brakes like a dream now. Next is valve cover gaskets as the oil leaks a tiny bit and you can smell it in the cab. As the discussion starter posted, I have always notice the idle noise and when you push in the clutch the noise goes away. Maybe this will fix that all?