I see it with the car's shadow on the road.

 

Shiny black SUV reflections on the highway are the easiest way IMO. It helps if you're only going slightly faster than them, or pace them, but then you risk looking like a stalker.

 

GoPro Hero2....works perfectly.

 

I'll wrap this up as the OP from my trip today...

1. Dark SUV - maybe I'm driving too fast, but by the time I can catch the reflection on the slab side, just can't seem to see it clearly amid all the creases and lines on the SUV or vans. I tried both the driver and passenger sides. I didn't want to be seen as a creeper admiring my own reflection on their car.

2. Tape - 3M blue painters tape worked well. But less satisfying than visual confirmation.

3. Kid in the car - would have worked if my bum of a son stayed awake long enough. He was snoozing before I got through the tollbooth.

4. Camera would have worked great, but I didn't have one handy and didn't monkey with the iPhone mount long enough to do it.

5. Stainless steel container trucks - this worked the best. It's amazing how many of them are out there if you are actually looking for them!

So my spoiler was working fine. After I visually confirmed it on a stainless steel truck a couple of times, I didn't notice the high velocity lift any longer. I swear the older you get your mind starts to play tricks on you. Thanks for all the suggestions!

P.S. I did see from another search result that one person claimed if you're tall enough you can see it in the rear view mirror. I could not for the life of me replicate that.

 

Have your wife, or anyone else, drive the car and you can follow behind or turn around in the passenger seat and look.

 

Glad you found out that it does in fact work.

Are Euro cars the only one that have a button to raise or lower the spoiler manually? My old 996 had it and a 997 I am looking at has it too. Note the button on the lower most row, all the way to the left.

If you had that button, sure would have been easy to find out, no?

 

Yes all the 996/997 models have the button to raise the spoiler but you have to be able to see the spoiler to know if it's actually up - hence all the suggestions about cameras. reflections, someone following you, etc.