I bought a low mileage bmw 320 LPG car, similar economy to diesel but no DMF, DPF, EGR, HP fuel pump & injectors, turbos etc to worry about. Its also a timing chain but is a manual so still has a clutch to change at some point.
Downside is it has a small ish range of ~200 miles and the rear dampers are worn out, probably from the extra weight of the lpg tank.