Commutting by bus vs ride sharing with colleague's car?

Hi everyone.
I'm about to start a job, which is 8 miles away from my house and out of town.
I don't have a car, but the HR person told me I will be able to rideshare with someone.
I've done the math and it is the following:

BUS - change two busses and walk nearly a mile to work and then back. - 15GBP per week. Takes 1hr and 15 minutes.

Rideshare - walk to coworker's house and pay him 25GBP per week, 5GBP each day. Takes 30-40 minutes.

My own car - Most comfortable but most expensive - 60GBP per week with initial investment for cheap car and insurance and tax. 30-40 Minutes.

I don't want to be driving my own car to work. I hate the stress and having to pay so much for a car. However I also think that my coworkers will probably give me lifts for 4-6 months and then will ask me why am I not spending my money on a car and stop giving me lifts...

I'm thinking of using them for lifts for as long as possible and then just getting the bus. What do you guys think? I really don't wanna drive and sink all my money into a car just to get to work but it will obviously save me time.