Channel 4 has several clips with some narration from Matthew on their website. Watch and listen to the clips here.
Edit: it seems this is a weekly series. Matthew Macfadyen has narrated episode one from last week and episode two this week. Another episode takes place in Australia, next week.
Cassangel just heard Matthew Macfadyen's voice narrating a programme called "Dangerous Jobs for Girls" on C4+1 at 10 - 11 pm. Its about 3 English girls who are giving up their usual lives and jobs to go logging in British Columbia.
Cassangel's other half thinks he may have heard Matthew in a new car commercial as well.