If you can afford to attract attention, an electric or plug in hybrid car may be a good choice. There are some used ones available, perhaps for as little as $100, if you are confident about your ability to fix or modify. Typically they are cheap because the battery is marginal or worse. If it won't run at all, you can't really determine how much else needs fixing. Some rather small light weight lithium ion batteries are available at better prices than last year. So you take out the old battery and install lithium ion batteries to total the same or slightly more voltage than the original battery. I think you figure 3.6 volts per cell, but according to one source the 50 cells should stop trickle charging when the total voltage reaches 210 volts = 4.2 volts per cell. Possibly the original battery was more than 200 volts. If you have to build your own charger, a full wave bridge rectifier will trickle charge to a bit over 320 volts with nothing, but a fuse or circuit breaker in series, with 240 volts input. Multiple batteries are good as you can lift them without a fork lift or equivenent and you may decide to sell the first vehicle and buy a different one with a different battery voltage. Do get all the same amp-hour rating, preferably with the same cells. Most lithium ion battery packs come with installed safety devices which will possibly interfer with charging the packs in series. Your range may only be a few miles, but now you can test drive the car and the existing systems. It should perform better than new with the reduced weight. The over charge protection may not be adequit for the lithium ion battery, so you will have to be careful about over charge.
More likely the chargers that you got with the car won't fully charge your lithium ion battery, but 80% or so charge is fine for lithium ion batteries, except for reduced range. They are best charged early and often. Most of them are damaged by discharging below about 3 volts per cell. Even undersized by amp-hours, they can easily provide more kilowatts than the original battery and can be charged safely to about 90% in minutes instead of hours, if the charging system can produce 50 KW or so. Likely you can't get 50KW from your main circut breaker in your house until you pay your utility a big bundle of money for an up grade as 50 KW is about 220 amps at 230 volts, which is likely more volts than you will get from the utility companies transformer at 220 amps, even if your main circuit breaker is 300 amps.
Possibly you can attach a plug to hybrid that was not designed to be a plug in = voids the warenty, but likely there is no warenty on a used hybrid. Needless to say the electricity is dangerous; besides high voltage there is enough current to throw great balls of molton metal. Please correct, refute and or embellish. Neil