I have musician earplugs, but they irritate my ear badly. Plus they give a pretty bad occlusion effect so I can't use them in meetings, since I have to talk a lot there ... I have a speaker option, but almost every time I am on the phone, someone else in the office is also on the phone or talking to another person, so I hardly understand my phone - and when I use the ear capsule, I also have to turn the phone up to understand it against the other voices ... which is so dangerous ... I hate navigating through this f*cking everyday minefield without a detector ....
You may need a different size of musician earplugs, or a different brand. The one I purchased came with 3 sizes, and while I guessed I would have needed a large, it turned out the medium was the better fit.
Raising the volume of the ear capsule as you describe can be potentially damaging, and is hard to measure objectively the db's of. I would suggest you avoid it for a few days and see if it makes a difference. You describe raising the volume which I think can be damaging.
@Bill Bauer
No argument if you or others feel the need to drive with protection. There are many variables, including the type of car and the engine and its condition. Also the amount of traffic can figure into this. I am fortunate to have a newer car with double laminated glass to reduce the noise. I do keep the windows up to reduce the wind noise. I am relating my experience that I do not believe driving the car has caused any issues for me, although certainly others could be more sensitive.