I was just curious as to why the OP said no to a search. I don't see why, if you have nothing to hide, you would say no to a search.
Because I don't want evidence planted in my vehicle.
Because I've got better things to do other than sitting in the hot sun on the side of the road while Barney Fife uses my vehicle for his fishing expedition.
Because I have better things to do than sitting on the side of the road for ANOTHER hour putting my crap back in my vehicle because Barney was mad he didn't find anything.
Because I don't want Barney fiddling with the gun I always have in my vehicle. Chances are he doesn't know the gun laws and doesn't know me keeping a loaded gun in my center console is perfectly legal.
Because it's my damn right to refuse a search.