I like the 1st and 3rd, the 3rd looks slightly comical with the officer standing in the car, Number 2 would be stronger as a tight crop on the small group with the flag the fellas in front don’t ad anything and the leg poking in behind them is a little distracting. I think 4 and 5 suffer as you can’t see the full vehicle.
Out of interest why do the flags have CCCP on them I thought that stopped with the end of the Soviet Union (always thought CCCP was the Russian shorthand for United Soviet States of Russian).
The convertible has a funny number plate – Parad(e)… :) And it’s a four door convertible, an unusual model, probably custom made. All subjects are impressive, not very often you see so many relics of the past. You had a great opportunity.
As for photography, I like picture no.2 for its unusual depth of field. Did you played with the blur tool? because the white markings on the street are not sharp and they should be under their feet, like in photo no. 1. It looks unnatural, but interesting though.
I would use a neutral density gradient filter for sky shots (in no.1) which is overexposed.