I have an MDX and RDX with the beak. When I detailed them the first time they were both clayed with Pinnacle Clay and then polished with Pinnacle Advanced Finishing Polish. The RDX was then sealed with two coats of Griot's Liquid Gloss Poly Wax (paint and beak), and the MDX received two coats of Wolfgang Deep Gloss Paint Sealant. There were no problems (streaking) with any of the aforementioned products, and they did not alter the unique brushed finish of the beak.
The detailing was done nearly a year ago. I plan to repeat the process in Sept, or Oct. In the nine or ten months that have passed I have washed regularly, and added liquid and paste wax when I felt the sealants were starting to give out. More often I was looking for an excuse to try out a new product. I have used Collinite 845, Wolfgang Fuzion in both spray and paste, all with good results.
I never felt any of these applications left the beak with excessive shine, and nor did any of them change the look of its brushed finish. I will not hesitate to repeat the process again this fall.