One advantage Bonnie and Clyde had was that cops did not have license plate scanners on the roofs of their patrol cars. Today, no matter how anonymous their car was, unless they swapped plates often (and swapped them with plates from the same make, model, year, and color as theirs) the cops would still be able to locate them pretty quickly.
A second advantage they had was that if you could get away from the cops who were chasing you in X-county, Wisconsin, the cops in Y-county, Iowa wouldn’t find out that you were wanted for a fairly long time. It was very easy to just disappear back then. Nowadays, Bonnie’d better hope Clyde doesn’t have a cell phone or they’ll get caught that way. Along the same lines, CNN did not plaster every photograph ever taken of you on international television 24/7 in the 1930’s, so the average citizen would have no idea who they were looking at even if they happened to catch a glimpse.
Of course another advantage they, and all of the other gangsters of the era, had was that if you went to St. Paul, MN you were almost guaranteed to not be arrested, as the police there had a deal with the mob: Refrain from committing crimes here, and we’ll look the other way when we see you. Today’s Bonnie and Clyde would have no such safe haven and would probably have to spend some of their earnings on a below-radar plane ride out of the country when things got too hot.
Were I going to go on a cross-country string of murderous robberies, the type of vehicle I had would be largely I think irrelevant beyond needing to be reliable and with tinted windows so people couldn’t see me too easily. The electronic toys inside would be much more important. I’d want a few radio scanners to give me an idea of when the law was closing in on me. I’d want a rotating license plate system so that I could have a different plate every 50 miles or so (this system actually exists! It’s basically a bunch of plates on a rotating drum - hit a button and it flips to the next plate. Commonly used by spies in the old days - might still be used now). I’d want it to be off-road capable because, let’s face it, I’m probably gonna have to cross an international border without using roads if I really want to get away.
But realistically, after I kill 30 people and steal a few million from a bank, my getaway vehicle is going to be a 737, coach, to some island in the Caribbean that doesn’t have an extradition treaty with the US.