When in doubt, I always like to give the power to the numbers.
I recommend you do some homework before you sit down and talk to your husband.
How much would the car cost? Would you pay using your savings or get a loan?
Write down a few scenarios showing the money you can spend or save if you buy the car now and if you wait 3-5 years.
Savings left in the bank earn a little interest and provide invaluable peace of mind.
A loan involves monthly payments and charges interests, increasing the actual cost.
What else could you do with that money?
Talk to your husband with your notes in front of you to support your point, and together compare the different scenarios.
Maybe it's worth to wait and use the money for something else, or maybe you decide to wait to be able to afford a better car in a few years.
It could be that you decide to go ahead and make the purchase now, it's all good as long as you both agree on the plan.
Good luck finding a nice compromise that makes both happy.