It's not accurate to say the car and DNA are "what we have". It's what we've been told about, which is quite different. They have already stated there is a lot of information in the Probable Cause documents, which are still sealed. NONE of that information can be shared with the public until it's unsealed, so a LOT of their evidence cannot be shared.
DNA is not a weak piece of evidence at all, but it depends greatly on where that evidence is found. Does anyone think they would have arrested him on a no knock warrant, 2500 miles away if they had found his DNA in the kitchen? Or the carport? Or on a porch column? Of course not. It's a known party house. The DNA will HAVE to come from a place that can't be explained by a normal, brief visit to the house.
Plus, no LE and/or prosecutor is going to try their case to the media and general public before the trial. It would taint the jury pool. So judging the strength of their case by what allowed them to obtain a warrant would be a significant mistake.