I don't but there's a '08 V6 with the Pony Package that has them at my work. I've seen them driving around at night and they don't look like very good HIDs, like slightly brighter than the normal headlights.
I have the HIDs on my 08. Between the rental mustangs I've gotten without the HIDs and mine, there is definitely a huge difference, but I did expect the HIDs to be a lot brighter than they are.
The 08 Stangs have reflector HIDs which are inferior to the projector HIDs commonly found on foreign cars (they have a noticeable aspherical optic). You're losing a lot of light through the inefficient reflector design. Overall it wouldn't be a bad idea to shell out $500 for the factory HIDs, but I wish Ford went to a better setup. Even the lowly Mazda 3 and Mazda 6 can be loaded up with projector HIDs.
The 08 Stangs have reflector HIDs which are inferior to the projector HIDs commonly found on foreign cars (they have a noticeable aspherical optic). You're losing a lot of light through the inefficient reflector design. Overall it wouldn't be a bad idea to shell out $500 for the factory HIDs, but I wish Ford went to a better setup. Even the lowly Mazda 3 and Mazda 6 can be loaded up with projector HIDs.
Have you ever seen a projector HID the side of the Mustang's headlamp though? Ford would probably have to change the internal housing and redesign the whole lamp so that a projector HID could be fitted and it probably wouldn't look similar to the way the current Mustang headlamps do.
It should be better than the halogens, but Ford could have gone to an even better projector HID setup. They sort of half-a$$ed it. It's similar to removing your stock H13 bulb and replacing it with a HID capsule. Yes you get more light than stock but it could have been much much better.
I prefer mine to the stock halogens on other Mustangs that I test drove, but they're not as good as the HIDs I had on my '00 Audi S4. One thing I noticed is that they have a softer "edge" than other true projector HIDs - the Audi had a definite edge to the beam with a noticable stairstep pattern.