There are a couple of 996 for sale in my area with factory installed areo kits that make them look like GT3 cars. They say that these kits were installed at teh time of purchase by the dealerships, so I'm wondering if this is a rare option and would make them worth more in the long term?

Thanks

 

I don't know if it will increase the value but here is my opinion. Anything not factory installed is aftermarket, even if the dealer does the work. And, a lot of people looking to purchase look for all or as close to original as possible. Just my opinion.

 

There is an option code that will tell you if it was factory installed or not. In our case it was P06 (GT Package), but there were some others too.

Check the sticker in the frunk or get a dealer to pull the build sheet for you and that will if it was factory or post-build.

As far as rarity, they aren't common, but I wouldn't say it's uncommon. The X51 and sunroof delete were much more rare options. Much like the headlights people seem to either love or hate the aero kits.

 

MKI & MKII are different. I did extensive research on this.
A lot of deviation on MY02 & MY03.
During this time period there were two different side skirts and two different rear spoilers.
Also, MY01 started the elimination of air skirts behind rear wheels, but they were still showing up on MY02.
The front bumpers stayed consistent.
MY02 - MY03, the Aero Kit II could have been ordered with the Carrera Wing or the taller Wing.
The code sheet under the front hood could have various codes, depending on how manufacturing order was processed.
There could have been one code for Aero kit or separate codes for the individual pieces.
Actually found a car with a code for Carrera Aero II, which indicated the Carrera Wing to be utilized instead of the taller Wing.
My 2003 (early production), came with Carrera Wing and side skirts.
In 02/2014, I discovered that Porsche had 10 factory GT3/Aero bumpers left. 1 in Philadelphia, 2 in Atlanta and 7 in Germany.
I purchased the one in Philadelphia.
Thus completing the Carrera Aero II configuration of my car.
I have recently seen an advertisement for someone that has (3) Aero/GT3 bumpers for sale, I don't know if they were Porsche or aftermarket.
IMO, if you upgrade your car with a option that was available for your model year with all factory parts it would not be a negative. But, with respect to 996tt post, it is true that you would be modifying the factory building of your car.
An example of option upgrade I did as well as bumper was the factory option of footwell lighting.
All factory Porsche parts from switch to bulbs.
Would this hurt the resale value of my car? IMO, I purchased my car for me, not the person who will own it next.
Do what pleases you!