You probably have some old car that is on your dream car list. It might be a '69 Camaro or it might be something weirder like a VW Thing or you might be Ralph Lauren, in which case your classic dream car is all of them and you already own that. You picture yourself with a sexy person or totally non-sexualized dog in the passenger seat cruising down a beautiful highway with the top down on Sundays, simply having the time of your life.
The reality for most classic car owners tends to be a little sadder than that. The dream for most is of driving the car, but the truth is that owning a classic is usually more like taking on an expensive mechanical hobby. The crazies embrace this whole-heartedly and purchase an MGB, which can usually be found either disassembled in a garage under a drop-cloth next to an uneven number of wheels or sitting on the side of the road with the engine stopped and the windshield wipers impossible to stop. Normal people just get a Mustang or or a Bel Air or a BMW 2002.
It's common advice to set aside $2,000 - $5,000 in addition to the amount you paid for your classic to immediately put into repairing it. If you're lusting after something exotic, like that old Lamborghini you drive by every day or a Ferrari, set aside about five times that much. This is, assuming that you plan to do some of the work yourself. If you don't, set aside more. Also, get ready to do some of the work yourself... it's inevitable.
Owning a classic can significantly impact your lifestyle by virtue of stealing all your time and money. It's like buying a child for $12,000 on Craigslist.
Much like children, classic cars also attract tons of unsolicited advice and attention from complete strangers. Everybody loves it when your weird neighbor waddle-struts onto your property wearing some denim shorts and a unevenly buttoned flannel shirt while stroking his unkempt mustache and starts yammering to you about lawn mowers for as long as you'll let him. If you're working on an old car in your driveway you can expect that same neighbor to tell you about how his Plymouth Superbird made 1,200 horsepower and got 60 miles per gallon because "da gubmint dint put no cat-ee-lit-ick convertah on it" before he sold it and bought a certified pre-owned Prius.
At gas stations, you'll attract record numbers of young men who will say the same five things to you. These five questions are often different depending on the car in question so I'll use a Dodge Challenger as an example:
"Does it got a hemi?" (Bad grammar is par for this course)
"How fast does it go?"
"Are you Bo or Luke?"
"Ugh... I bet you get horrible gas milage."
"Can I take it for a spin?"
Since your old car is an old car, you'll probably go to the gas station quite regularly, and these questions will get very annoying. You'll start making 2:12 AM trips to get gas just so you don't get mobbed by anyone.
On those rare days off that you don't have to spend covered in grease trying to concentrate while Bubba tells you about how carburetors can cure lymphoma while a 16-year-old boy you don't know tries to borrow your car, you will grab your wife/husband/girlfriend/boyfriend/friend-with-benefits/dog and go for a drive, and you'll love it. The question is: is this worth it to you?