Unfortunately, now that you own a roadster, there's no viable, affordable supercharger option. Clearly the extra $10K for the SRT-6 is better and cheaper than the aftermarket. But you'd have to dump your existing roadster to get an SRT-6, and you'll take a financial beating on the depreciation. If you were starting from scratch, the SRT-6 would be the way to go. Don't hold your breath waiting for DC to release an add-on SRT blower.