There are two differnt outfits making the Charger and 300 into convertibles.
One is ASC and I forgot the other one.
One method is to use that big ugly roll hoop. It keeps some sense of structural integrity and keeps the car 5 passenger.
The other method does not use the roll hoop. Instead they greatly strengthen and enlarge the driveshaft tunnel to add rigidity. You don't get the hoop but you lose the rear middle seat thus turning the car into a 4 seater.
With both conversions the rear seat becomes much smaller and way too upright to sit back there for long stretches. You also gain a couple of hundred pounds in weight.
Most of today's modern designs look bad in convertible form. That is because of this trend of high beltlines and small greenhouses. this causes what I call "the Erkel effect" where the beltline is pulled up so high it looks like Erkel's pants.
The classic elegant convertibles (60s Corvettes, Mustangs, jag XKE, etc) all had low beltlines that looked far more elegant and gave riders much better sightlines.
The other issue is the current trend towards oversized wheels also raises the beltline.