In financial terms - your DH is correct. You are not overdrawn or in debt, you have some small savings, so you are managing. You think it is 'tight' because you like spending money and don't like being frugal.
You only want the extra money to spend on "nicer" clothes and car. These things are just status symbols. You didn't even say you wanted the money to spend on activities with/for the DC, which might have been a worthwhile choice.
HOWEVER, these decisions have to be made jointly. He can't just decide what to do and over-ride you.
You both need to sit down with your bills, bank statements and a spreadsheet, and set up an annual household budget. In the budget, include a monthly 'allowance' each for adult clothing and personal spending (fancy toiletries, coffees, cafes, hobbies, phones, new tech, socialising etc.), an amount for DC activities, and open up a new savings account for the 'next car fund'.
If you can't discuss it and agree, then I suggest you go to counselling together - big differences in values and attitudes to life take a toll on the marriage over time, and if you are not careful can cause resentment.
Resentment kills love.