I am about to finish paying off $25K in debt from various sources, including a repossessed car. I’m planning to be debt-free by late September and want to finance a $15K ATV with manageable $240/month payments. My credit score is around 580, so I’d need my parents to cosign. Will making on-time payments on this loan still help improve my credit, or does the fact that my parents are cosigning mean I won’t see the same benefits?
Yes, it will boost your credit regardless of whether you have a co-signer.
Nevertheless, this is a horrible concept. If you have to finance a toy for more than four years, you cannot afford it, and your credit rate will be exorbitant. I would not co-sign for you if I were your parent. I believe your mother is using an excuse to avoid co-signing. While her stated explanation is incorrect, her underlying conclusion of not co-signing is correct.
Instead, focus on saving, building an emergency fund, and getting yourself back on solid financial footing, rather than diving back into the hole now that you have finally gotten out.
This is very sound advice. If you want to become debt-free, that is excellent. Then create an emergency fund, set aside funds for retirement, and budget money for pleasure so you can save up for a secondhand ATV or whatever. Financing something for $15k out the door is ridiculous, and it is the salesperson’s job to convince you otherwise. It will not be merely $15k when you need components, repairs, accessories, or a better trailer.