The telemetry feature is in the 2007 Charger R&Ts and Daytonas and any Chargers that have the EVIC (Electronic Vehicle Information Center). However, it is not available on them in the 2008 models. For some reason, they are disabled. You can see them, but they do not work. Only the dealership can enable them using Starscan.

They are still functional in the 2008 Charger SRT. Owners that have EVIC, just have to hold down the Nav and Music buttons on their steering wheel for 6-10 seconds to obtain a new series of options are available on the EVIC. They can then scroll through the menu using the up/down arrows. To return to the normal screen, they just have to push the "N" button.

I assume the Challenger SRT will have this same feature, especially because Dodge is using the Charger SRT guages.