Since when do you have to do a sobriety test? At least from my understanding you don't(correct me if i'm wrong cause it would be good to know).. At least from my experience(in Texas, Travis county).. I've gotten a lot of speeding tickets.. claim my amendments(cars never been searched.. even though I don't have anything to hide thats a huge pain in the ass) go to court if I have to and clear it up really quick. Slightly inconvenient but its better than paying for a ticket or having it on your record.
And as far as driving under the influence of alcohol... my policy is say no to the breathalyzer and when they arrest you, say no to the blood test. You spend one night in jail and have your license automatically suspended for 3 months.. its better than risking a dui(not saying I dui or support it... but shit happens)(also this happened to my friends brother recently and I'm not sure if thats exactly how he went about it but his licence was auto suspended for 3 months so its very likely it is.. I could ask)
Same guy got pulled over when he was younger.. and stupider as far as his rights. Cop searched his car found marijuana and claimed "plain sight" etc..(after the fact lol) that kevin was talking about.. but he beat it in court.
The system doesn't completely screw you if you don't let it.. cops will try and nail you but you can usually find a way to beat it if you don't screw yourself for no reason.
Thats my 2 cents