Taxis, called Karwa taxis, are mostly publicly operated by Mowasalat, and can certainly be purchased in the Karwa app or even a call centre. There's also numerous privately-run taxis in the country, and Uber operates in Doha. Jeep Wrangler costs in Qatar have stabilised in the final couple of years, https://www.strongrentacar.com/en/rent-a-car/small-saloon