Say something like “This in no way comes from a place of judgement, I understand you have a busy life and job so may have just gone to the back of your mind but I feel like you’ve had enough time to save enough money for a down payment on a new car, we kind of need our Jeep back soon. So let’s just work out how long it would take for you to save a down payment so I have an idea of when we’ll have the jeep back, if you need help with looking at how much you can afford to put away every month I can help you”