I love DAB as home radio & have splashed out on a DAB/CD/FM & docking station for ipod which lives in the kitchen,(great for cooking & drinking) cost £70 & sounds like a £300 set up. I've no idea on incar DAB. I'd like one but have only seen the highway add ons. What have you got & how much was it?
If you can pick up stations in the car that you can't at home i can only guess it's because the car's moblie? :-/
My Home radio is also in the kitchen - me too!

My Car head unit is JVC. (exact model and cost don't have to hand) the first H/U was a JVC AX11 something which has a screen on the front and was linked to my reversing cam and DVD set up.
I returned it (several times (sigh))as it wouldn't display properly unless you held your finger against it (made driving quite interesting!). :-/ :-/Got swapped three times and I never want to see it or the W****r that did the install ever again.

It's now got a proper DAB bee sting aerial and is working magnificently!

(If you go for an in car DAB radio, for gawd sake don't be persuaded to use the stupid bits of string on the windscreen jobs. They're a waste of time

)
DAB on Wheels(dot) com have lots of info about in car DAB
Decent head units for DAB (so I'm led to believe) are JVC, Clarion and Alpine.
I don't have any experience of the pure highway type radios.
I'm sure there are people on the forum that do - perhaps they'll let you know what they think of them?
Hope that helps!
Matthew