What kind of protection for painted matte finish?

[Ebf2k]

I have a aftermarket fiberglass diffuser on my Corvette that is painted in a matte black finish to resemble factory ABS plastic.

What's a good product to use to protect this finish and keep it semi-glossy? I've been using Aerospace 303 up until now but it doesn't last very long and I'm not sure it's the right thing to use on a painted part.

Suggestions?

Here's a pic of the part in question:

 

[spiralout462]

How about Permanon Super Matte? I have a sample but haven't had a chance to use it yet.

 

[jamesboyy]

Take a look over at chemical guys they have a matte sealant its called JetSeal Matte Sealant and Paint Protectant its pricey at 38 dollars but for 12 months of protection it's something to consider

 

[davidc]

If it is painted I would think any wax/sealant would work. If it was truly plastic then a protectant. Your choices are unlimited with paint. I had asked Duragloss about this at one time and was told to use DG 101. If I were to use that suggestion I would use DG 601 bonding agent also which greatly extends durability.

Dave