What is the difference between "showy" and "flashy"?

Hi, I know that the words are very similar in meaning, but I would like to understand the subtlety of differences in meanings between the two words. I want to double-check my understanding with you guys. Is it correct to say the following:

Flashy is very similar to showy in meaning (in that both usually suggest poor or cheap taste that are aimed at drawing attention), but flashy suggests showing off things in a louder or more obnoxious way than showy.

Could you guys please correct my understanding if I'm wrong. Thank you so much!