Well if you drive one of these i would say yes....
http://www.slipperybrick.com/wp-cont...ummer-limo.jpg
But i think the 12" is about 1.5m long plus the base, so aim for a station wagon/4wd or similar. We have an Astra and the 8" is maxing out the room available when we take it anywhere (OTA secured along the back seat and the base in the boot).
Something i read when i was planning to buy my scope
"The scope that is best for you, is the one that you will use the most"