what david said. i stop speaking, and give myself a moment, then start again slower.....it seems to help
A speech therapist I know said to practice speaking SLOW, LOUD, ARTICULATE, AND PAUSE OFTEN. It has helped me. I also sing a lot when alone.
Keep practicing your breathing exercises and work those diaphragm muscles as much as possible. Don't be embarrassed to sing out, LOUD, and practice with family members and friends. Sing, sing, sing! Be joyful! My dad and I love to do this together and just be silly...
I've had PD for six years but nobody notices except when I have trouble talking. I do the LSVT exercises about 5 days a week. And like you, I do LSVT while I'm driving, but not when I'm at a stoplight to avoid freaking out other drivers!
I did Big Loud therapy with my therapists and it's still helping a lot. I practice the loud speech and reading loud almost daily