This is a bit of an odd one really.
I've got a couple of opinions on it. First off M badges by themselves are a little pointless IMHO, they don't really mean anything, but if you want them and it floats your boat, and your car has some BMW Motorsport products on it then it is perfectly justified. The point where I disagree I guess is when a badge is stuck on a car where it has nothing of said design or product on it?
I used to have an E36 M3, the 3.0. It had the Evo touches to it though even although it wasn't, I didn't have a problem with that tbh as it was still an M3.
I knew about four people from the BMW club who had non M3 cars, but they were badged as M3's. Shock horror I hear you say. Well yes and no. First off if someone has put the time and effort into making a geniune looking replica, then I have no problem with them badging it up as an M3, as long as it is not a chav wagon and as said it looks like a stock geniune M3. IMHO it is a form of flattery. The point where I disagree, is when you get the boy racers in their aweful atempts at 'copying' an M3 and not making a replica, I.E they do some of it, the rest either looks odd or 'not right' or they ruin it by putting lots of chavtastic bits on it. Then of course they try and race everyone on the roads with their 120hp, and it gives the M3 a bad name.
I don't mind people who make replica cars, everyone does it, replica ferraris that are badged up and aren't, replica lambos, lotus etc etc. I haven't got a problem with it at all if it has been done properly. So the difference here is seperating the enthusiasts from the boy racers thats the key.
As another example, if someone went through the time and effort to make a flawless copy / replica of a LHD E30 M3, I wouldn't have any probs with them badging it up to complete the look, I would take my hat off to them for doing such a good job in replicating the original probably.
In closing there are two types of people, the type who puts an M badge or M3 M5 etc and thinks it makes the car have an extra 100hp, or the type where they love the look and style of that car, go through the effort to make a very good replica and just enjoy it.
I sold my E36 M3 when I moved house as it was more important and I needed the money. Owning several cars now, If I wanted to I have the cash now to buy an M car if I want, but I didn't want the crazy costs associated with some of the parts that I experienced before (1200 for a cat alone and 750 for each manifold!), and the insurance and hastle. But I do now own a replica M5, with everything done, even down to the number plate surrounds! It has M equipment on it, M5 suspension (not EDC), even although it is a smaller lump, I'm not ashamed to drive it around, I love it! It does now has a BBTB, remaped ECU, 2.5 ported intake and us M-spec cams for the M50, putting it around 250ish hp and similar torque I would imagine (not proven), not up to real M5 power by far (like 100hp shy of the 3.
but still good enough to put a smile on my face and the best bit is it looks fantastic, and I lurve it!
but if your just putting the m-tech badge on there as you have m-tech parts, then why not??
... i think that this all badge thig is stupid, to me most important is the car and the performance