Re: searching the tanks.... Not that I'm aware of. It's something I've been saying for a while that they need to do.
As far as clothing might float... he stripped down to nothing if we're to believe that the clothing in the road is something he did, and not staged.
The crash site is north of Luling so unless he passed the crash site, turned around (more than 5 miles from where he should have turned right to stay on the main highway), and crashed going south.... I'm going to venture a guess that the vehicle was going northeast as I do not believe the car passed the site after driving over 5 miles down a gravel road, then turned around. Also, there are skidded tire tracks from the south.
I doubt it took him ~5 miles down a gravel road before someone would determine they missed their turn.
Lastly, I'm not convinced it was him driving the car down SFR. All we know for
sure is that HIS car drive down SFR and crashed, and HIS clothing and beta were found on the road. Sure, one could assume that it had to be him doing that but not necessarily. His digital footprint ended back in town so he might not have even been alive as someone drove his car down the road to abandon it. So much is unknown.
I agree on it smelling pretty nefarious. I also believe whatever happened started back in town and that Luling (perhaps the park the car passed by?) was where whatever happened began.
And just so you're aware.... I got in the case from the get-go and it's driving me nuts too! LOL