Bad weather, bored Googling led my down some rabbit holes of future project ideas for a second, 'sportier' 500 toy. That led me back to Zcars and their Hayabusa-engined 'kit'. I've looked at this in the past, and even emailed the company to no avail, so I was just curious if any of the UK members knew more about it, had seen any in the wild, or what. It seems they do actual Mini stuff, but I haven't been able to find anything concrete about production Fiat 500 stuff.

Just curious on what the UK rumor mill says or if you'd seen one out and about. No intention to buy one anytime soon, just wondering.

Hi Matt;
I met these people at Brands Hatch during the "Abarth 70th birthday" event. Their stand was just round the corner from the (35 car) classic Abarth display. As I was showing my car in the display (and having it taken round the track), I wandered round to look at their products. They seemed quite well engineered, as far as I could see from what I was allowed to look at. I was very interested in their 'wishbone' suspension and enquired as to the possibility of purchasing a crossmember and a pair of lower wishbones (I already have a pair of 'coil-overs'). Although I followed up my enquiry with a polite "very interested" letter to the manager, like you I received no response--nada, not even a courteous acknowledgement.
All very well putting a 'REALLY quick' engine into the back of a 500, but people forget---as well as going VERY quick in a straight line, it also has to have a cornering abaility to complement the straight-line capability, and the 500 is just too short to achieve that.
To prove that point; many years ago somebody put 1/2 a Cosworth BDA engine into a 500 (the other half of the engine had been destroyed in an engine blow-up). It was very quick in a straight line, it was almost uncontrolable through the bends---and I have the article on that particular car if anybody wants a copy of it.

There was a guy in Australia who posted on the old Fiat 126 UK forum a few years back. He did a bit of drag racing and as a project he fitted a 1300 Heyabusa engine into a stripped down 126 (Niki in Oz). He told the scary story about how he had the engine and transmission all hooked up and took the car out to a disused stretch of motorway near Sydney for a test run. He got the car up to some incredible speed then realised he was running out of road so hit the brakes which were the standard drums. A couple of the drums disintegrated but he just managed to avoid disaster.

I have this pipe-dream, master plan for an autocross, track version 500 with proper brakes all around, modernized suspension, steering, a roll cage, and some unnecessary amount of power. Something similar to the Hayabusa kit, but maybe not that extreme.

Fear not, I wouldn’t chop up a quality car and would find a proper donor. It’s that or build a kit car a few years from now.

What you might be able to do is take a leaf out of the Poiish rally boys book. They heave the 650cc engine out of a Fiat 126 and replace it with a Fiat 'Fire' engine---which is a 1098cc 4-cylinder water-cooled engine. They use a 'sky-hook' rear mount for the engine and tune the engine. With wishbone front suspension (and lowered all the way round), they make a very 'cost effective' 1st rally car---and do they go! There are quite a number of u-tube films regarding these cars.
Now, being that the 500 engine is basically the same as the '126' engine, and they are mounted in their respective vehicles in exactly the same way, I can see no sensible reason why one couldn't carry out the same "performance enhancement" on a 500. Lowered, with 'wishbone' front suspension (and coil-overs), disc brakes up front, C/V type drive-shafts, and a water radiater where the spare wheel would normally sit, it would be a very quick, and interesting, project

It might be worth having a look here for some inspiration:
http://www.retro500.com/home.html

The guy who created this site built Nigel's fire 1108. A lot of work went into the brakes and suspension on this as well.

I have one of the Scooby 1800 lumps ( was all rebuilt)... it s a common conversion for VWs in Australia.. real compact unit...
adapter plates are a simple flat alloy affair....

Somebody has already fitted one of the smaller (and non-turbo) 'scuby' engines into a 500---it is more than quick!