My husband and I are flying into London and, upon arrival, want to immediately get to Oxford to pick up our rental car. It's our first trip to England, so we don't want to drive (on the other side of the road) until we get away from the city. Our destination for the first night is Chipping Campden. We are currently signed up with "We Know Group, Ltd" for transportation from Heathrow Airport to Oxford. Has anyone used this service before and was your experience a good one? If not, can you recommend a driver service or would you simply take a taxi?
You're wise to postpone driving after an overnight flight. I don't have experience with the service you're signed up with, and I wouldn't think of paying for a taxi to Oxford. This bus service is reliable, comfortable, and would be my choice to reach Oxford directly from LHR. You might consider spending your first night in Oxford before driving on to Chipping Campden the next day, for your and others' safety.
A taxi from LHR to Oxford would be foolish and expensive.
When RU going?
Take the bus or go by train.
Take the 15 minute Heathrow Express ( book NOW for cheaper rate) to Paddington Station. Then Take the Great Western train to Oxford.
Or catch the bus from LHR to Oxford. Use the website Link Dick provided above.
Heathrow to Oxford via Paddington sounds like to much faff to be worth it. Just take the coach (bus).
And staying the first night in Oxford and picking up the car the next day sounds like a good idea. Not just for safety but because not seeing Oxford is a bad idea.
We Know Group is a transport company with its base at Heathrow Airport and seems pretty centred on London to me. Not to say that they wouldn't be efficient at airport transfers elsewhere. However, the bus is regular and pretty simple to do: stand 15 at the Central Bus Station for Terminals 2 &3 and Stand 10 @ Terminal 5. Website: https://www.oxfordbus.co.uk/airline/