First post after much lurking... wish me luck...
Hey man, sorry to hear about your situation. I was in your position while going to school. I was living in my car, had no money, and couldn't look to my parents for help. If you have the right attitude you will work yourself out of this. To that end:
PRIORITIES
Your first priority is to get a job. Spend all your time applying for jobs. Spend the rest of your time looking for more jobs to apply to. Take anything that comes your way even if it's a temporary position. Don't tell anyone at an interview that you are homeless or in any state of distress.
FAVORS
Be very tactful when approaching your friends for help. Someone below said, "If they're true friends they should understand". That's not how the real world works. This is your problem, not theirs. Friendships have limits. Being homeless will test those limits. You're not the guy they had a few beers with last week anymore. You're the homeless guy, and you'll need help, and they know that you might call them. You don't get to tell your friends how they "should be" when you're homeless and asking them for favors. The last thing you want to do is show up at their door with a sense of entitlement. They might do you that first favor and then find excuses for anything further down the line. You'll wonder why. Use them only when you absolutely need to and ASK them for help. Don't demand it, expect it, put pressure on them, get angry with them for refusing, whine, etc. Just ask and be very grateful if you get it. If they can't help you still thank them for considering.
I don't recommend that you stay at anyone's place just because you are not used to or comfortable in the car. That's not sustainable. Sooner or later you'll have to leave just like you already did with one friend and you'll be back in the car. Except now that you've already stayed there for X days you'll be much more uncomfortable asking them to take you in again later. Might as well get used to the car ASAP and use your friends' places when it really matters - like having a job interview the next day. That's when you should ask your friend to spend the night. You want to get a good night's sleep, shower, iron your clothes, etc. They'll be much more likely to say yes if you show up rarely and with purpose and you won't feel like you're freeloading. If you don't have an interview the next day, rough it out in the car. Remember, it's your problem, not theirs.
MONEY
If you really only have $140 you should minimize your expenses (gas, cheapest food you can find, coin laundry, etc) and you'll still need money very soon. You have a few options: 1. Credit cards - do you have any? This is where they can really help. If you have a $4000 credit line you can use it while homeless and pay it off as soon as you get that job. You'll might rack up interest but you have bigger problems to worry about and you're only 25. You'll pay it off. 2. Borrow it from friends - if you can. Again, you have to be tactful. Money is the shortest path to ruined friendships. Don't assume they have $X to give you. Justify your request. Look at your expenses and decide how much you need for a month or two. Call as few people as possible who might be wiling to lend you, explain how much you need and why, and ask them if they can give you $500 or whatever. If they don't have that much, ask how much they can help you with. Assure them that paying them back will be top priority. Write them an I.O.U. even if they insist it's not necessary. It will show them that you are serious about paying the back. Don't go silent for months with people you've borrowed from. Ping them every couple of weeks, let them know you are working on getting them that $100 back or whatever it is, give them $20 if you happen to have it that day. All of these are critical in establishing you as a dependable borrower. You might need $50 today to fill up your tank, but tomorrow you might get a $500 traffic ticket or something more serious. When you approach someone who lent you $50 before to ask for $500, you better have made that $50 loan a risk-free and pleasant experience for them when you had it. 3. Bank loan or any other loan - I made this my absolutely last resort option when I was homeless and didn't take any out.
COPS
If you are homeless long enough cops will eventually talk to you. The most likely scenario is that you'll be sleeping in your car somewhere in the corner of a parking lot thinking you found the perfect spot until you're woken up at 3AM by a loud knock on your window and a flashlight in your face. For me that happened on day 1. I had a blanket with me just like you which was a dead giveaway that I wasn't exactly on my way home. Make sure you don't have anything to be ticketed for like broken lights/expired license/expired registration/etc. Be super nice to the cops regardless of your personal views and politics about them. You are in a vulnerable position and they are in a position to bother you. In some cities there are municipal codes that make it illegal to sleep in your car so even if nothing's wrong with your car you aren't necessarily off the hook. Don't piss them off.
FINALLY
Be strong. This is your first night. You will encounter problems that you didn't think about. You gotta be ready to put your emotions aside and handle them. Your resolve is all you have. You can crush this or you can let it crush you. You have to decide that this is not going to continue any longer than it has to and methodically go about your days solving this issue. Once you are back on your feet you can spend time reflecting how you ended up here and if there's anything you could've done differently. For now, forget about your ex and how much money she blew or what have you. Spend all of your focus and energy on the actions and people that will get you out of this, not the ones who got you into it.
Best of luck.