I've been using one of the Jconcepts roller bags for the past 6 months and I can fit 2 cars, setup board, transmitter case, battery bags, spares case, small spares containers in the side pockets plus a large tool bag in there easily. Brilliant build quality too but at around £90 still pricey
http://www.jconcepts.net/shop/jconce...ium-roller-bag
or,
I have one of the LMR rucksacks (now sold by nemo
racing)
https://www.nemoracing.com/collectio...-car-carry-bag
this will carry 2 cars and tools/batteries pretty easily, or everything you might need for a club night (one car, TX, spares, batteries, tools). Only £40 too.