After the piece is COMPLETELY cured, you can wetsand with 1500 grit, then 2000 grit until the surface is smooth. After that, 3M rubbing compound does a great job of taking off the haze that wetsanding leaves behind. You are now done!!
This is the piece after final wetsanding. (note how much smoother the reflection is) Just to make sure that there are no problems with this weathering and turning yellow, it is a good idea to have a paint shop spray it with a U.V. inhibitive clearcoat.
If you have any questions, feel free to ask and I'll do my best to help out.
-Jason