Two men deny raping and murdering Quyen Ngoc Nguyen, whose body was found in the burning car.
Bolton edge past fellow Championship strugglers Sunderland to secure a first win in four and move up to 19th place.
The singer opens a centre to help young people in her home city of Newcastle.
A member of the public found the drugs in a carrier bag.
The bands of leather are "probably the only known surviving examples" of their kind.