This really depends on the driver. I have no problem in Fiat 500 (because they have long, flat seat squabs that are adustable for tilt), or on Peugeot 308. I guess that Volvo V40 will be good. Depends on the multi adjustability of the seat and how you adjust it as well as the hardness of the squab. Ideally the front of the squab should support your thighs and the backrest should be slightly reclined so some of your weight is fed into the backrests, not all of your weight fed into the base of your spine. (Advice of Dr Mark Porter, Britain's leading vehicle ergonomist.)