How can wife make long trip by automobile with urinary incontinence problem?

Hello there!Sorry to hear about your situation. As a caregiver, I know that when using "disposable briefs" really helps a lot when travelling. You can find great brands at the Pharmacy. Hope that helps

Yeah, are you not using disposable incontinence products? They are nothing like you may remember from years ago and they range from very stylish and discrete to ultra absorbent. You can also get washable or disposable pads to cover the car seats just in case, And plot out your route in advance to include places to stop for a washroom break - chain style coffee shops or fast food places are a good place to stretch your legs and have a snack as well as find an accessible washroom.

There are some very good Incontinence briefs "Pull-Up" type that would work.
Stopping at least every 2 hours. Does not matter if she has to go or not stop and she can go to the washroom and check the briefs. Some are so absorbent she may not even know they are wet. A

How long of a car trip are you planning? If it is more than a 1 day trip would flying, taking a bus or a train be easier for both of you?
Is there a younger person that could drive you both? and help both of you at rest stops? (Most places now have "Family rest rooms" that you could both use together)

I probably would not do the urinal bags they would be difficult to secure in a car and the chance for spilling might be high.
There are pads that you can sit on just in case a brief leaks. But frequent stops and changes of pull up would be the best way to avoid accidents.

Mom does quite well with the things already mentioned, disposable incontinence briefs (she finds Depends work best for her but there are many choices for a personal preference) Ultra or overnight might be best, either reusable or disposable pads for the seats as an extra precaution (both available on Amazon) and stopping every couple hours which is better for both of you anyway. I would stat away from bags or bedpans especially in the car. If she wont try the newer disposables for some reason they do make reusable cotton incontinence underwear but they require much more work (storage for wet or soiled ones, washing them) especially for travel.