how do 6th orders respond in trunk cars

[jroo]

Over the weekend heard a 6th order and was really impressed. Thinking of doing a single sub set up in a truck car and want to know will it respond in a trunk? WIll look at either a single SA 10 or SA 12. I know the box for a 6th order will be larger, but the trunk in my Volvo S80 is pretty large. I guess I should also ask about Sundown SA series in a 6th order? I have heard they do pretty well in them, but want to make sure? Looking over the web, I see an old PWK 6th order for a SA12 that shows a pretty good response graph. Looking for similar in terms of something that will play from 70 down and have pretty good low end as well.