For the garage or for the trunk? That will make a huge difference in the group's recommendations.
Assuming you mean for travel, I was taking a good look at the stock jack in my Volvo. It's like a scissor screw-operated jack, but it's only half the size and folds up into itself. It easily compresses to 2.5" or 3" and extends as high as you would ever want a roadster on the side of the road. These jacks have been around Volvo for a while, so the chances of finding one seem good.
Just my .02