To add what might be an important wrinkle to the discussion, generally, for evidence obtained under a search incident to an arrest - for such evidence to be considered permissible - the search must be incident to a LAWFUL arrest.
Which leads to other considerations and particularly consideration of the exclusionary principle known as "fruit of the poisonous tree."
Simply stated, bad arrest = poisonous tree - and generally evidence obtained from that unlawful arrest is considered fruit from the poisonous tree and inadmissible.
http://topics.law.cornell.edu/wex/fr...poisonous_tree
http://legal-dictionary.thefreedicti...oisonous+fruit
It may be much simpler (and considerably cheaper) to be a Luddite.
