> The price ($10k) is good enough that it's under my impulse buying threshold for cars.

I'm not even sure where to start with this.

I hope it's just my wording that is throwing you off.

Say, for instance, you need a car. For me, if a car costs more than $10k, I really have to think about how reliable it is, what features it has, and generally if I am getting value for my money. This is all because anything over $10k is going to take longer for me to recoup. This is what I'm defining as my impulse buying threshold.

Not really that weird at all. Cars maintain a healthy resale market so if you buy a car with a couple of owners and a lot of miles for $8,000 and drive it for a few months, you can often sell it for the same, or just a little less, than you paid for it. It's not an $8,000 gamble, it's more like a $500 gamble.

Your impulse threshold is about 3x my ceiling price for a car.

If your ceiling is $3333, maybe you should stick to riding a bus. Do you realize how much it costs to run one car for a year? Gas, registration, insurance, oil changes, maintenance, it adds up pretty quickly.

What would be interesting is if it could carry a small electrically powered compressor that you could plug in for emergencies.

I think this is exactly what the electric motor does: compress the air if you run low.

Wait - you want to use a battery, to power a motor, to compress air, to then power another motor?

No - I meant powering a compressor using mains power.

Most petrol stations in the UK have an air compressor that you can use to top up your tyres. I wonder if these could be re-purposed.

I'm pretty sure you don't top up your tyres to 20MPa (~200 bar)

Yep, 2900 psi; and I just read that they plan to upgrade to 4400 psi tanks.

For reference, I put about 40 psi in my car's tires.