The '10+ bodystyle doesn't pull off the wingless look as well as the earlier S197s, or the previous generations for that matter. But most of the factory and aftermarket wings are absolutely HUGE for these cars and IMO they're a bit heavy-handed. I like the basic GT rear spoiler on mine, it gives a nice balance and proportion to the rear of the car. I have seen a few other options that look good too, but in general, smaller=better.
