I reckon anyone would agree with me that, when you're doing a conversion, modification, or even a restoration (whether you want it to be original or upgraded slightly for the sake of improvement), one of the very first things you need is information. Accurate information. Information that is actually correct, rather than something that's hearsay or based on assumptions that come from working on totally different cars.
Having made that statement, and believing it because I think most of the other things you need are only useful after you've got the knowledge to apply them, ain't the 'Net grand? In particular, if you're thinking of doing something that's slightly out of the ordinary, it's really quite important to be able to find out exactly how something can be (or should be) done. For example, my (probably foolish) plans to modify an old 2-door Volvo; who on earth modifies those? Well, people do modify them, but that's usually by putting them into a ditch, cruising across intersections without looking and applying their nose to other people's doors, etc. Around here, people certainly don't modify them on purpose, and certainly not for extra performance!
So here am I, driving around in a car that'll keep up with traffic, but which isn't exactly a powerhouse. And I'm already missing the turbo all-wheel drive Liberty (and I still do; watch out RS Turbo ... ). But having garnered the flicker of an interest in what you could possibly do to a Volvo after the research I'd put into buying one, I went on a search around the Web, and found quite a few resources and a few mailing lists devoted purely to Volvos. And even the modification of said Volvos for the purposes of extra performance. Schweeet ... freaky, but schweeet! Now, I know when I bought the car I did float the notion that you could drop in a later model 740 Turbo engine, fiddle around with a bit of wiring and the boost, and end up with a comfy 200hp 240. But at that stage, I didn't really imagine I'd really be thinking seriously about it. And it was the extra info that I've been slowly collecting from the Internet that has pushed me into taking the next few steps.
I suppose that if you were building something relatively common, for example if you were working a 302 or 5.0 in a Falcon or Mustang, or you were doing something with a Holden 308, 304, or the ol' faithful Chev small blocks, you should be able to find someone locally that will know exactly what to do, or at least exactly who to talk to in order to find out. And car clubs are of course a really great way to find out what you should be doing, or the products and methods that have worked for other people. Especially if you're on a budget, you don't want to get too experimental, because mistakes and fabricating or buying new stuff can really jack the cost up.
However, I really don't feel all that comfortable with joining a club and suddenly annoying the living crap out of the other members. It just feels like you've only joined to suck all the juicy info out of them, plus the fact that you don't necessarily know who to talk to about any given item/topic. These aren't big obstacles of course, but they're little things that might slow a less motivated person (like myself) down. Instead, joining a mailing list or a forum that concentrates purely on your type of car means that's all the other members want to talk about. You don't feel any obligation to the social side of things if you're not that way inclined; and it's amazing what information turns up when you're talking to others around the world.
And the more you hear about how people got 450hp out of their car by performing Procedure A, Procedure B and following Plan X, the more you realise how you'd be interested in doing similar things. And you can also start to figure out how you're going to do them yourself. In essence, without such a great source of information there's no way I'd have as much of an inkling about what works and what doesn't, which parts are strong and which could be worth replacing, which parts are interchangeable, and so on.
For example, how much of a pain it is to fit the locally-available factory turbo engines from newer models; and yet how the motor in the car at the moment is strong enough for a few Bar of boost (with lower-comp pistons of course), so all the effort putting in the later-model engine might be wasted under certain circumstances. And also things like which head castings to use, because some years the heads had smaller coolant passages and are less likely to break under boost.
And very importantly, the Internet lets you find global sources for parts. For example, with such a small market in Australia, things like forged pistons are a custom job for most European makes unless you know where to look, and that can be very expensive indeed. By comparison, I can get in contact with a company in Europe that makes the pistons to suit the mods I'm performing, and even with shipping costs I can save myself 70% of the costs of those pistons.
Having said all that, I don't think the Internet can be a complete replacement for the car club. It's still good to actually talk to people about their experiences, and it's also great to have someone recommended to you to do some of the work. Someone in a club near you is obviously going to be a better person to ask about where to find a good spray painter or a mechanic - than people halfway across the world from you! But it's still the case that without the information available, I wouldn't have had the first idea about how I could do anything half-interesting with the car, let alone actually starting on getting it done!