Had a rethink re car charging. I have in my arsenal a 37W Victron Inverter. I’ve noted that the AC180, when charged in silent mode regularly draws 280W (240VAC). Given the efficiency loss of an inverter I calculate that the DC current draw of the Victron will be approx 28A. As my Auxiliary battery is on a 40A 8AWG cable from under the hood it is more than enough to use to run the Victron either direct from the vehicle or alternatively from the Aux battery, when driving. I know it’s not the most efficient, but 280W of AC input is as good as if not better than what I might get with a DC converter and I already have the gear. 
Definitely the cheaper way to go. I have several step up DC to DC converters which are capable of delivering the full 500 watt input charge rate (12-48 volt) so it is possible to increase if you ever have a need to do so. Increasing charge rates also mean increasing wiring size and having a cooling fan to supplement the DC step up converter.
That my 375W Victron will supply the 280W to the AC180 is enough for me, as I calculate may daily use will be <500Wh.
Breakfast - boil water for a coffee, 1,000W kettle = 100Wh and electric toaster = 80Wh. Total = 180Wh.
Lunch (if used) - Toasty Sandwich maker = 100Wh
Dinner (if used) - Microwave approx = 140Wh + another coffee = 80Wh. Total = 240Wh
Daily total approx 420Wh, at 280W input = < 2 hrs to charge from the Victron and I have 110W of solar I can plug in when not driving.
That sounds like a long-term wise solution. I think I would trust the Victron inverter for long term heavy duty use more than I would Noname step up converter’s