Okay, thanks for the advice.
How do you measure tinnitus loudness anyway? For example, I can hear it at 75dB in the car, at least according to my mobile.
If the car noise feels too loud to you, or if you get spikes following car rides, you will want to wear hearing protection in the car. It doesn't matter what the actual dB reading is.
I always wear ear protection in the car. I thought I didn't need it once and got careless, and it did indeed spike the T a bit. I just keep a little pair of good ear plugs in the side door. That way I never forget it.