Shahidul Ahmed, 41, was put on trial after DNA evidence linking him to Rachel Manning's death was discovered following his arrest for an unrelated matter in 2010.
He hit Miss Manning repeatedly with a steering lock after she was dead, causing broken bones, Luton Crown Court heard.
DNA found on the steering lock matched Bangladesh-born Ahmed after it was discovered by the road on the direct route between the spot where the body was hidden and Shahidul Ahmed's home.
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