Headlights - I’ve used a Ceracote product a few times on my vehicles. It’s about $25 on Amazon. Costs more than others, but it’s the only one that I used which actually provides good results. Just follow the directions closely and don’t rush through the early cleaning steps. Worked really well on my...

Sounds eerily similar to a problem I had with my 04 xc70 a few months ago. In my case it ended up being a burnt valve. If you going to be switching around the ignition modules anyway, your just 5 spark plug removals away from doing a compression test. You can get a usable on for about $25 on Amazon....

I bought a 2004 XC70 with 78k mi in 2015. Had a burnt valve at 193k in 2021. During that 115k period I owned it, I ran primarily 87 octane. Valve seals were definitely becoming worn at time given the oil consumption was steadily increasing. Approx 1 qt every 2500 mi. It was also really cold when the...