I paid for my college expenses myself by having a 35 - 40 hour a week job and cleaning cars on the weekend.

Don't hold me to this but somewhere in the neighborhood of around $12k to $15k a door ( meaning if it's a two car garage then it's a two door garage) And the exact opposite can apply.

It sounds like it's not really necessary, unless you have cars parked on them, and in this case, they are for a back yard patio.

Not sure how many college kids have cars there or what the market is like near college campuses.

I've been investing for a few years now, Eric, and I've implemented all of the following advertising methods, (I've also hired people to do many of these for me):  direct mail, bandit signs, car magnets, posters, flyers, card drops, t-shirts, door knocking, cold calling, cinema ads, craigslist posts, email alerts, and online ads.  

Junk SoftwareConnected Investors Deal Dog software (web-based)Thread started by Carly Umberger where she explains how she got ripped off and many people agreed:https://www.biggerpockets.com/forums/79/topics/446571-connected-investors-deal-dog-web-based-software-review

Second, the neighbor was a car mechanic and every day the house was busy and noisy.

We have fallen behind on our mortgage and both our cars.

He mentioned 3 things that received heavy resistance when they were first introduced but are now so common place that we can't imagine life without it.Banks ATMs, cars, and I can't remember the 3rd one :-(Cars are so common place now, can anyone believe they were ever met with resistance when they first came out???

I have a couple of cars that I am renting out through a peer to peer site called "Turo" (think of it as AirBnB for cars).