What can I do to keep my 1999 Nissan Maxima running?

I can't save for a down payment on a new car for at least six months, and I'm worried about my Nissan staying in working order until I can do that. Here are the issues: 171,000 miles Two bent axles, but nothing at risk of falling apart (tires wear quickly, though) Unseen oil leaks and leaks from radiator... show more I can't save for a down payment on a new car for at least six months, and I'm worried about my Nissan staying in working order until I can do that. Here are the issues:

171,000 miles
Two bent axles, but nothing at risk of falling apart (tires wear quickly, though)
Unseen oil leaks and leaks from radiator hoses, pretty major
New ignition coils, engine mounts are good, but car is shaking badly and computer says two spark plugs are misfiring

What can I do (cost-effective, efficient) to keep this poor guy running until I can afford a new car?
Update: I bought this car over a year ago for a great price (KBB), but these problems came up as time went on. I've had mechanics tell me not to even bother with maintenance, but I can't believe that's an option.
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