My wife and I have had to bear the burden of an unused second vehicle through the "economic downturn", for almost 18 months now. We hope to sell it soon. We bought it used for about $19k, and the monthly costs are $470 a month payment plus insurance ($80 a month) annual taxes ($190). so, without even driving it, our annual cash outlay is about $7,000 - a portion of which is "equity"
So at the moment, not only am I using a bicycle as my primary transportation, I have a four-wheeled money siphon sitting in the driveway because it is difficult to find a buyer (and it is doubly difficult to sell it living at a distance from home as I am at the moment).
So, yeah. I'll be money WAY ahead when I get rid of that. If I were to lump everything I've spent this year getting the entire family set up with bicycles and accessories, I'm money ahead in less than a year. Let's be fair and account for the fact that the second vehicle (if driven daily) would be owned for 8-10 years beyond the loan payoff. Even with that, the average annualized cost after selling it (if it has any value at that point) would still be about $2k-2.5k a year, not including fuel.

I did the old POS car routine for a while, and it is not as cheap as everyone thinks it is. Initial cash outlay of $500 to $2000 is typically followed by another $500 to $1000 to bring it up to good serviceable condition, followed by $750 to $1000 a year for annual maintenance costs/oil changes (assuming it is driven daily). Let's say $1700 to $2500 a year if you assume said car will last 3-4 years before dying completely.

Our primary car is a prius and costs considerably less than our second car (a 4x4 Nisan pickup). Well, until the time comes to replace our batteries :O

I'm not completely buying the "heaps of extra groceries" argument, because it is a small increment in my case. YMMV, but not a big issue for me.

I know this topic has been discussed ad nauseum before, as it is now (and I'm now contributing to the ad-nauseum-ness). Here's my quick take.

- I made the mistake of getting a second vehicle. I am not likely to repeat that mistake.
- I could completely replace my sub $2,500 commuter (with bells and whistles) almost three times a year and break even with my present cash outlay to own my undriven second vehicle, and probably once a year compared to the "prorated" cost. Of course, I have no intention of doing this.

Yeah, the math is pretty easy in my situation.

If I were splitting hairs of transit versus bicycle, I really wouldn't care about the cash part - it is more about the health benefit and joy of riding at that point (for me).