Is a husband's behavior of changing new cars every year, which leads to financial loss, considered a Shariah issue despite his not falling short in household duties, Zakat, and Sadaqat?

Moderation in spending is the Islamic approach: no extravagance and no miserliness. The limit of extravagance varies according to people's different statuses; what might be extravagant for one person may not be so for another. Renewing a car annually is not wasteful if it does not cause hardship to its owner, and the husband should be advised to economize with gentleness and kindness. However, if it does cause him hardship, then it is extravagance that must be abandoned.