Local dealership has a S197 Mustang ~2006 model that caught my eye the other day. It's got a billetish grille with the Mustang emblem offset, raised spoiler, 18 inch wheels, matte black spoiler and I think some kind of stripes, leather etc. etc. All that stuff looked OE, and had it been a manual I would have been really interested.
My question is, is there anything out there that jumps out that would tell me I have a Mustang on hand with the Performance Package? It's really the one I'd rather have.
Well, besides this.
The V6 Performance Pack didn't appear until 2011 
But I think you're asking about V8's (except for the odd V6 Teralingua you pictured), what you found is a sticker and tape package called the "CS" or "California Special", which is a great way of assuring that your V8 Mustang does NOT have any performance packages (you cannot order the CS with the Brembo's or the Recaro/Torsen, etc).
Now, on the GT's, there is no "Perfomance Pack" per say, there's two good options (these came in 2010 or 2011): the Brembo brakes (easy to tell, look at the front calipers), and the Recaro/Torsen package (easy to tell, look at the seats).
The 05-09 GT's only performance "option" was a different rear gear (3.31 and 3.55 were offered IIRC) and the only way to tell is to crawl underneath and check the tag on the rear axle.
Happy hunting!
Oh and, I don't know how the heck to find a 2011-2012 V6 Mayhem Mustang. You'd have to like measure the sway bars and brakes or something else odd like that. They really should do something with them...
This wasn't a CS car, I remember those, but it didn't have GT on it anywhere, and I don't think it had a sticker that said which engine it was. V6 premium maybe?
And I was referring to the V6 with performance package. I like the V8, but I think I'd rather have a Mayhem Mustang, for the lighter front end and all. Which is why I pictured the Terlingua.
The 06-09 V6 Premium was called the "Pony Package" has a tape stripe with "Mustang" on the rockers, a GT spoiler, and little foglights in chrome surrounds:
Regular:
Premium:
It still had the same cloth interior (leather optional), suspension, drivetrain, etc.
As for your mystery car, CS's usually don't say GT on them anywhere except in the middle of the stripe where they say GT/CS. The only other option is the 08-09 V6 "Appearance Package", which was a bunch of random stuff from other Mustangs like a CS grill tacked onto a loaded V6 premium. They only made 152 08's and 96 09's.
Appearance Pack:
Info:
The easiest way to spot a 2011+ V-6 Performance Package is to look at the wheels. The 2011-2012s all came with these 19" wheels which they shared with the GT/CS:
The 2013s also have 19" $teamroller$ they share with the GT/CS (shown below):
Other than that, the best ways to tell from the outside are by the larger V-8 front brakes and black wing mirror housings. If you can get a look under the hood, the Perf. Pack. V-6s have a factory strut tower bar and unique engine cover:
All V-6 Perf. Pack. cars have the 3.31 rear-end gearing. IIRC, there should be a marking from the factory on the axle telling you what gear it came with. 3.31 gears were optional on base V-6 Mustangs, so it isn't a reliable indicator. Finally, 2011-2012 V-6 Perf. Pack. Mustangs were only available with manuals. The 2013+ are available in both manual and automatic.
I have a 2013 V-6 Perf. Pack. Mustang on the way. It should be here sometime next week.
EDIT: Wanted to add the whole list of go-fast parts the V-6 Perf. Pack comes with:
Shelby GT500 rear lower control arms
Mustang GT front struts and rear shocks and springs
Mustang GT coupe front and rear stabilizer bars
Mustang GT front and rear calipers w/ Performance Friction pads
Front strut tower brace
3.31:1 rear end ratio
19" wheels with Pirelli P-Zero 255/40-19 summer tires
Two-stage electronic stability control with a unique sport mode
