Not being sarcastic at all...

No, I did the oil change and don't buy that far in advance. Still holds...after that long? that'* great.

I've been known to buy in advance. I usually get my Mobil 1 at Walmart, since that'* where it is usually cheapest. So, if I know I have an oil change coming up in a month or so, I pick up a 5 quart jug and a filter.

I've used Slick 50 in my cars for years with excellent results based on knowledge and lab testing.
First off its suspended in 30w oil and has PTFE suspended in it along with a bonding agent.
While working in the Torrington / Fafnir bearings lab who makes the roller lifters for the 3800 we tested plain engine oil vs Slick 50 and cycled the bearings the equivalent of 100,00 miles. There was no comparison on wear. Slick 50 outperformed plain oil by 2 to 1.
The reason you probably don't notice a difference with it is because its lubricating during a dry start up when all the oil has drained into the pan overnight. This is when most engine wear occurs.
Never had an engine wear out yet period.
Just my 2 cents worth.

Too add my testimonial,
I used it in our brand new caravan and 3 days later my wife hit something that tore a quarter sized hole in the bottom of the oil pan. She drove home the 10 Miles and told me the oil light came on. I turned the car on and sure enough it was on, hehehe. I popped the hood and pulled the dipstick and there was nothing on it. I looked underneath and found saw the hole right on the front bottom edge. Not a drop of oil on the driveway tells me she was out for a while. I patched the hole with some JB weld and aluminum; 8 years later and 72,000 on the odometer and not a tick to her, we traded it in for an 2000 Astro AWD (Which my wife promptly totalled followed closely by the new Buick, hence the used Olds) But yes, it lived up to its promise!

And it will from the TRULY independent testing. For the first 100 or so miles, then it all comes loose and clogs up your oil filter. Read the pressure drop testing in the links I posted on Page 1.

And read carefully DuPont'* stand and issues with it'* use. As well as the FTC going after Slick50 for false claims.

Heard a similar story at the 1/4 mile modified track. The guys modified looses all oil pressure yet he finished the race without oil. Slick 50 did the trick.
I only know my own eyewitness testimony is I never had a clogged filter and allways get good pressure.

Myself as well.

It made a difference in my case. The cold weather lasted more than 100 miles and it still started like a warm summer day. Never clogged a filter on me either.

Good, bad or indifferent? I guess this is down to interpretation. I have yet to find a person I've known that said it was proven to have harmed their motor.

I do know that Duralube is an everytime additive that seems to do nothing for cold starts where I was concerned.

Guess this one is a toss up. As a club we should probably say that we've heard good and bad on it. Use at your own risk. (It'* in my car, might be a few years before we know the long term results)

All street cars have a bypass in the filter or filter mount. The filter could be pluged solid and not show a noticable change on the guage.

Can't tell you how much I like this product.
Consider these examples.
80 Skylark 2.8l valve train is tight and timing goes off 3-4 deg. yr.
One treatment 10 yrs ago and timing hasn't moved since. Allways 7 BTDC.
90 SSE, 90 SE 88 Park, power steering pumps whining. Steering rack fails on Buick 2 yrs. Flushed and install slick 50 PS formula and no more problems in any car.
80 Buick steering tight on cold mornings, PS formula installed, no more problems.
These lab testing results are probably the same as the EPA who cannot even get the fuel economy numbers right.
In my opinion if you select the right additive you can enhance the performance of any automotive system. Just don't use oil additive that use chlorinated solvents as they will corrode the inside of your engine.
As Bill stated above though, with any additive "use at your own risk".