I started a new job five months ago- It's retail. It's quite far (40 minute drive), but at the time I needed the money. Financial context is I now have another part time office job within walking distance and don't 'need' the second one.
Last week my car had to go to the garage- Today it won't start. It's an early 2000's Peugeot, not worth fixing at all and my best bet is selling it for parts.
I don't need a car- This one was an old family members I just took on. I'm also not in the financial position to buy one.
My only issue is that my other job is an expensive, hour and a half train journey. I will be spending more than I am earning, but my notice period is five weeks. (Not sure why it's such a weird amount.)
I have no clue what to do now. 
I can't travel in and they were aware of my car problems but refused to engage in conversation when I told them there was a chance my car wasn't fixable and might cause an issue earlier on in the week.
AIBU to ring my manager and say that I can only give four days notice? Or would I genuinely be expected to drag myself on the train for three hours a day and spend more than I'm earning on a ticket?
If it makes any difference, the company also regularly underpays me and has had very little regard for me the whole time I've been here.
I feel very awkward in this situation but I genuinely don't see another option- I've already been told a transfer nearby isn't possible as well.