There are a lot of Extractors out there.
I personally have a Mytee HP60 Spyder; a nice sized machine that has pretty decent pressure and really great water lift. It has a water heater and that also helps in cleaning and rinsing/extracting.
This machine has done a zillion cloth interiors and almost as many canvas convertible tops. It really does these better than anything else I have ever tried.
It is not cheap and the tools for it are expensive as well, but once you get it all set up, it works great on any kind of vehicle interior where cloth and carpeting are your cleaning goals.
You will want to research all you can learn about carpeting and cleaning, and the products that work the best for different kinds of stains, etc., when you get those high end jobs that mean everything has to come out perfectly.
It never ceases to amaze me after I use it in any vehicle, even those that look clean to start, at how much brown to dark brown to black water comes out of the recovery tank when finished. All that brown/black stuff was in the car floor mats and carpeting. No amount of scrubbing with a brush and whatever will really get that stuff you now loosened up out as well as an Extractor will.
Depending on how you use it, how much water you introduce into the areas cleaned, the ambient temps, is it sunny outside, etc., you may need to put a fan into some vehicles to blow air over the damp areas to help dry them out faster.
If you happen to live in a perpetually warm climate - Texas, California, the South, then drying times are much faster for sure.
There are other makes and all have different specs, pricing, etc..
I bought this machine because I didn't want to have to buy another one later, and wanted good pressure, good sized water tanks, water lift and heat, and several years have gone and it has been a workhorse that has never let me down.
All the motors are located and accessed easily in the bottom, and all can be changed out, etc., with little difficulty.
I love this machine !
Good luck with your research !
Dan F