From Exeter St. Davids train to Paddington (H&C Line)-Underground, Tube to London St. Pancras, train to Luton Airport Parkway Rail Station, then line 888 bus to Airport Bus Station. 3hrs 21min £60. From Exeter City Centre, Bus Station bus to Victoria, Green Line Coach Station then line 757 bus to Airport Bus Station. 6hrs 08min £44. From Exeter City Centre, Paris Street bus to Tiverton, Bus Station, bus to Hammersmith (H&C Line) Underground Station, Tube to Marylebone, Gloucester Place, then line 757 bus to Airport Bus Station. 6hrs 09min £43. From Exeter drive to London Luton. 3hrs 38min £44.