How should I deal with people who hand out unsolicited advice?

I have an autoimmune disease and suffered since age two. People keep giving me suggestions and advice on how I should handle my illness, etc. But sadly none of their suggestions I've tried and were unsuccessful. My mom's hairdresser whom I never met, keeps giving me unsolicited advice. I was shopping for a car. I had my heart set on a Civic or a Corolla. The hairdresser told my Mom I'd be better off driving a Volvo because Hondas are cheaply made, unsafe and get stolen while the Volvo was built like a "tank". I'm not the "street racer" type and I keep my cars orginial and take good care of them. She did all she could to get me into a Volvo and laughed when she heard I wanted a Honda or Toyota.

This woman also tried to tell me to stop eating Mexican food because it had MSG in it. I have tricuspid regurgitation causing chest pain, etc. I stopped eating Mexican food because of her suggestion and it didn't improve anything with my heart. Just before my father and I took a trip to Japan, she told my Mom I should be "easy" on my father and I'm not very considerate. My father and I take plenty of breaks on trips I mean, I hate people who form opinions about me, especially if they've never even met me. I know people have good intentions when handing advice but I take it as a form of discrimination against people with disabilities.

Smile and nod and promptly forget about it

Learn to treat unsolited advice like water off a ducks back

I expect that these people mean well and have your best interests at heart. Perhaps you can ask your mother not to discuss you with the hairdresser you have never met. If she is so clever, why is she a hairdresser and not a doctor or politician?!

"The worst vice is ADvice"! Simply thank them and say, "I'll consider that".