After the paint cleaner, if you want more depth, add in a light polish. Like I said, from a looks stand point, clay bar really won't change the paints appearence overall. It's the many steps I (and many detailers) take that make the paint look great and feel great. Skipping steps may get the paint 90% of the way there. Many customers don't know the benefits of a full detail until we do it, and they are amazed. Hooked. A guy ina 750iL knew his stuff, and wanted to know what clay barring was. I showed him on the IS300 I was doing (it wasn't a full detail, wash, 2 step wax, not clay barring) and he was amazed, and said he wouldn't have it done any other way. It's all in what you want, but it definitely has its benefits if your car is a few years old and has never been done before.

BTW: Your car looks awesome.