I changed my car just over a year ago. My previous car an elderly Volvo S40 was approaching 200,000 miles and was beginning to show its age. I had an Icom 706 MK1 in that car for HFas well as a Kenwood TMG707 for VHF/UHF. Fitting the gear was easy enough with space in the centre console for the two head units.
The replacement car a "second Generation" Volvo S40 (an old car in itself- a 2005 model) was a different proposition for radio. In the old Volvo there was a double DIN sized stereo, removing this left a space for a replacement single DIN CD/Radio as well as a space for a radio head unit. In the newer S40's there is no way of removing the stereo, it is built into the centre console and also controls the Aircon, heating etc.
I quickly realised HF would be difficult to install in this car so I settled on a dual band Icom 880 rig for VHF/UHF and it also has D star Capability. The body of the rig is installed under the driver's seat with the remote head mounted on a "Proclip" clipped to the centre console. the clip is a bespoke design for the S40 intended for use with a mobile phone but works just as well with the 880 head unit.