My favourite is lanolin-based products, i.e., the fat from sheeps wool). It is organic so does not harm nature, it flows out very well i kanals, crevasies and narrow gaps between sheet metal seams, it lasts for a very long time, it hardens to a very tough paste that is watertight still flexible and very resistant to wear. And stoneguard paint will stick to it. It is also easy to renew when a decade has passed.

Great job one place very important is under spare tire they are a salt collector an spray mechanism

Used same sprayer with fluid film this year also. Came out great. I reapply undercoat yearly. Some mechanic shops hate that stuff but I say great for rust prevention. One thing I did different was wear n95 mask and undercoated outside. Also my cars hood is aluminum so I don't apply coating to that. On thus car you have yeah that could use a coat since it's steel. My stepbrother has the same car but much rustier in NYS

Great job and .video. did you clean the rotors after this? How will you know if there is an oil leak in the future?