This BMW Z1 was my highlight of the Festival of Speed | Thank Frankel it’s Tuesday

You never know what cars are going to take your eye and, indeed, what you’re going to learn. I was for instance directed to two Series V Aston Martin DB4s, one looking like a DB4, the other essentially indistinguishable from a DB5. And then I remembered: it was only the Vantage version of the final DB4 that got that rakish nose. Then there was the Porsche 911, very nicely done as an ST replica, and an example of my perennial favourite, a race ready, Alfa Romeo Giulia Super complete with FIA papers. I’ve raced these many times in the past and have had more fun in them than many others costing many times as much. With a guide price of £25,000 to £35,000 I’d have the auctioneer’s arm off, if only I had both the time and money to race and look after it properly.

But in any such sale there’s usually a car that, for some strange reason you cannot really understand, just stands out. It’s the one that, hours later, remains front and centre in your mind long after all others have started to fade. It may not be a car you have always lusted after, nor even one about which you have devoted a moment’s thought for very many years. But once you’ve seen in and it’s got in your brain, there it’s going to stay. Such was my experience at the Festival of Speed.

It was a BMW Z1. Remember them? Cool looking car with doors that disappeared into the sills and to it look even cooler still. But just 8,000 were built as the 1980s became the 1990s, a fraction of what was originally intended. The reason was simple and had nothing to do with the car: it was just too expensive for the performance it provided: here was a car with just 168PS (125kW) from its 2.5-litre straight-six engine selling for the same sort of money that would buy you a 250PS (184kW) Porsche 911 or more.

I remember my first drive in one and feeling what a shame it was that its performance in no way matched its handling, which was simply sensational. It was the first BMW to use the soon to be famous multi-link Z-axle rear suspension and it revealed at once just how limited the previous semi-trailing arm systems had been. It had grip, it had poise, it had feel, it had everything… except the performance to go with it.

Apart, that is, from just 66 of those 8,000 cars. These were cars that were breathed upon by Burkard Bovensiepen’s then still private Alpina operation. These cars received engines enlarged to 2.7-litres, delivering more like 200PS (147kW). I only drove one once, and only briefly, but I was mesmerised.

Indeed what I remember even more than the extra acceleration and harder edged noise was the way the additional power gave the chassis the workload it was so clearly designed for and, together, produced a driving experience of rare quality. The fact it looked so cool and had funky doors was merely a bonus.

And that’s the car Bonhams was selling: one of the 66 Alpina BMW Z1s. It is of course possible that, 30 something years after I last drove one, I might think this one hopelessly slow and wonder what I saw in it in the first place. But I don’t think so: my memory is of a very special car with the looks, the performance and the handling to count as a minor great. And back then I didn’t even realise just how rare they are.

Even so, you wouldn’t find my paddle in the air, not even if I had the £80-100k estimated requirement to secure it. Because the truth is I have no idea what I’d do with it. And when it comes to buying a car – any car, for any price and for any reason – that remains the most important consideration of all.

Photography by Pete Summers.