What is oder for comparative adjective?

Hello, I have a question about usage of comparative adjective.

When I tried to explain some demographic group, I make a sentense like this.

Generation older than me does not follow the fasion trend.

in that case, why the subject is not used as "Older generation than me"?

Older generation than me does not follow the fashion trend.

because I think, adjective need to be sited before noun. such as "I want a bigger car than I have"

Thank you.