Help! My lab mix poops in the car!?

First to set your mind at ease Hw, Tape and even parvo have zero affect on the brain. Is is very likely she is feeling the change in your life/home. (the out of a job) and it is stressing her too. Just because its not her out of the job doesnt mean your now being home at different times and the stress you are likely giving off are not new to her. My only suggestion is to feed her once a day and early evening after all trips are done for the day and as you now a good outing before you leave. It wouldn't hurt to train her to go on command (take her out and give her a set word or phrase stand till she goes and praise like heck). This way you can get her to go before each trip. also a harness/seat belt to keep her in one seat with a water proof twin size sheet under her will save you some hassle till she gets things back under control.