Well, taking its still a fairly new car, engine bay shouldnt be that dirty. I would just use meguair's mist and spray and a micro fiber cloth to clean the painted areas or etc. You can also wax the painted areas to keep it shiny. The black plastic part, you can use armour type protectant
I would never use Armor All on anything. I have seen it double the speed of the breakdown of plastics. But you didn't mention them by name. There are a few good products on the market but not that one.
I used to work for a car care company that produced all this stuff (products like what Armor all is supposed to do and many other products). I also used it on my 1975 Datson B210, (bought new) before I knew the consequences of using it. Within 2 years, even though I used something to protect the dash from the sun, it started cracking. Within 3 years it had cracked everywhere. After I started working for the car care company, distributors that had been in the business for some time, stated that while Armor all sold well, they would never use it, due to what they had seen and feedback.
