No 303 doesn`t last as long in my tests unfortunately. If it doesn`t rain then it`s got decent longevity, but after a rain a lot of it is diminished. The bare bones lasts quite a bit longer probably because it`s oil based.
The only thing about that it can attract more dirt as it`s kind of "stickier" which is why I use 303 for the engine bay. I wish it would hold up to rain though.
I have used a lot of CG Bare Bones under the vehicle, or in fenderwells, (but NEVER in the Engine Compartment) in the Pacific Northwest, where of course, it`s raining, snowing, or always cloudy..
Never had much luck with the 303 line, so never followed up on it very well.
Griot`s makes their own version of this and I can`t tell them apart except for the cost difference..
The only other thing I used that was great for entire engines compartments, and all the black plastic in the fenderwells, was C/G Back to Black here --
https://www.autopia-carcare.com/black-on-black.html#.Wpc2CGpzb3g
Leaves a stunning look to very well cleaned German Car Motors and engine compartments, and wherever there is black plastic fenderwell liners, as long as you clean them really well, so it adheres better; it looks great, and lasts awhile.. It is not greasy, oily, or attracts dirt..
It`s not inexpensive, so you have to think about that if you are using it in a Shop vs my own vehicles, etc..
I used it in the Shop because my Client base loved it and could afford to help me keep buying it..

Just another option along with Sonus Motorkote which is also very good in my experiences..
The Absolute Best Smelling Dressing that if you leave alone to dry, will leave a beautiful finish that is not very long term durable -- Meguiars Hyper Dressing --- here ---
https://www.autopia-carcare.com/meguiars-hyper-dressing.html#.WpdpQmpzb3g
Dan F