I just use a 1 gallon size pump sprayer...spray onr to my car and use the vx5000 medium setting and wipe at the same time.
Are you using this method due to being out in the sun or are you just particular about using this method? Seems like an extra bit of work to me when doing the ONR wash in itself is just fine.
the vx5000 doesn't have dry steam function, so I am not sure. you should try it with dry and wet steam with onr and test us how it is.
what kind of towel do you use? do you steam and wipe? The steam is too wet so there is streaks? maybe you should slow down, have a microfiber and a ww towel in hand, steam, wipe and ww dry at the same time??