I tried the bungee thing and comparing the 2, the stand gives more support – it isn’t really on being tied to the side of the car so if you got over rough roads, it doesn’t bounce/rub or strike the side of the car…the wide base keeps everything stable and it allows a neat way of storing bikes in your vehicle…
Saying that, if you aren’t fussed about the interior of the car and/or don’t drive over particularly bumpy ground (to make the bike rock side to side) then bungees do the job nicely…
I’m in Central Scotland, so if you are as well, no probs meeting up to let you try it to see if the idea works for you…