My return to series in the car is currently alternating between Terry Pratchett's Discworld books and all of Christopher Brookmyre's early work. Both of them are an utter joy to listen to, and a potential threat to life and limb.
Car journeys here are, by necessity, long. Everywhere is around an hour away - at 100ks, on country roads, dodging potholes big enough to lose the car in, huge grain or hay hauling trucks, assorted wildlife from the kill you type (kangaroos) to the don't you dare kill them ones (echidna's and blue tongue lizards at this time of the year). It requires concentration, it requires focus. Tricky when you're laughing so hard you're crying.
QUITE UGLY ONE MORNING does a particularly good line in funny - provided gross, grotty and silly are things you find funny. Hearing the more grotesque, grotty and silly things in this book being read out by David Tennant made it even funnier.
If possible I'd forgotten how much I love Christopher Brookmyre's books. I am alternating backwards and forwards between these and the Discworld novels. I might have to start driving more.