I was wondering what criteria you savvy BP investors use to screen the buyers? 

You choose which property you want, which lender to use, which contractor will fix it up, where the rehab materials will be bought from, what the finished product will look like, how to screen the tenants and who the tenants will be, how much cash flow you will make, and on and on.

Have found great tips for screening potential renters on this site and look forward to using them.  

That's why  it is so important to do a good job of screening ANY AND ALL tenants!!

Could you do a screening print in the rear window of your vehicle? 

I can also verify the work going on at the base/contracts that are in place, just have not seen his directly.So what sorts of screening/verification should I ask for?

Cook County eviction system is rough as already mentioned here but that only makes us screen harder to ensure we don't end up in court.  

I have 2 top prospective tenants (the rest are screened out).#1: Section 8 tenant approved for 5 rooms. 

I have been doing all this for ten years: turning around and maintaining my units, screening and selecting tenants, moving them in and helping them move out.I've have had between two and eight units and have six currently.

There are many management companies in the DFW area so screening and selecting the right one that fits your needs is paramount.