I actually dislike glossy dashboards. When driving at a certain angle and direction relative to the sun, it actually adds glare and discomfort to front passengers. Many cars nowadays comes with non-reflective dashboard to prevent this. However, I've seen car owners, as well as some detailing shops, destroy the finish by applying Armor All or similar 'protectant' trying to force a non-reflective surface to shine and look clean and new.

I learned my lesson the hard way when I, like most teens of the day, didn't know better than to wipe the dashboard of our then new '92 Sentra ECCS with Armor All. It looked great at first but in just under a year, the grey dashboard got discolored (yellowed). The finish developed splotches and the glossiness became uneven. The dashboard ended up looking much more older than the car really was.

Since then, I never applied any chemical in car interiors. I just wipe it off with a damp chamois or a lint-free microfiber cloth. The most I've used is baby wipes to clean stains. But even that, I use sparingly. Now, the interior of my '07 Civic still looks fresh with its dashboard retaining its original color and finish after almost 5 years.

I only had experience with Armor All. But most other products in this category uses almost the same ingredients so I imagine that the end results would probably be about the same. But if you're bent on applying any sort of protectant on your interior, test it out first on a hidden or inconspicuous part before committing.