Spreading the word is getting frustrating

Well after almost a year of trying to spread the word about car seat expiration dates I am getting close to my whits end. I seriously don't know if I can handle another MOTHER telling me that she hopes my daughter is in an accident because I told her she was lucky it didn't happen to her child in the 13 year old car seat she had. Or another parent telling me I didn't know what I was talking about, and that plastic is just the same 20 years later. Ugh.
Its very frustration to see a 6 month old front facing, a two year old in the front seat, toddlers bouncing around in the back seat, a 20 year old car seat being used, but mostly its the ones that don't want to listen.
The most recent incident was a craigslist post where a mother was trying to sell a century smart move car seat that had been recalled in 1996. Not only was it recalled, but it was expired. I politely asked her to please check her manufacturing date and number to the recall sheet before selling it. She then proceeded to go off on me and that was when she told me that she hopes that something happens to my daughter, then she called me a crack whore. I don't know why people have to be like that, I was very civil and polite with her and just gave her the facts.

I want to spread the word about car seat expiration's but its hard when there are people out there that don't believe in warning labels, or the facts.
Its written on the car seat, and the manual.

Well....that's about it. That's my rant for the week.
OH We are moving in to our house this Saturday (3/7), and I will not have the Internet for awhile.