What kind of car?
Uniden makes the 510/520 that's small and Cobra makes a 19DXIV only slightly bigger. Both are much cheaper and durable than the 75WX ST and give you the option of changing out to a clearer microphone.
I used to have a Cobra 19, but now I've got a Cobra 29 in a MINI Cooper...

Obviously I don't need to make use of the back seat so this is a perfectly ok setup for me, I quickly learned where the different knobs where in relation to each other and I just let the mic rest under my ebrake handle between the seats while I'm on the highway. Saved me several hours of sitting in traffic on memorial day weekend.