There is one thing to remember about using roll under hydraulic jacks on small cars. If you have a flat tire the car is lowered enough that you may not have clearance to roll the jack under the body of the car. You can always dig out a little dirt unless the surface is concrete or asphalt. That's where some of the factory mechanical jacks have it over the hydraulic jacks. I used to carry a couple of blocks of wood to drive the car up onto to raise the car.
When I was living near the Twin Cities the hydraulic jacks didn't play well with the sub zero temps. That again left me using the mechanical jack till the weather warmed up. The Sears hydraulic floor jacks, even the new ones, would constantly fail in extremely cold weather.
That said, for years I carried HF low profile 1 1/2 ton aluminum jacks in my pickup and mini-van. Now that I drive a smaller car I'm just fine with the factory jack. Because of that the jacks are stored in the garage and used as needed only in the garage.
If you're dead set on keeping a jack in the car, I wouldn't hesitate to recommend the HF low profile aluminum jack. I far preferred these jacks over the 2 ton Craftsman floor jacks. Those were given to friends.