Time to nerd out: in the BMW world, Alpina cars are among the most valuable and thrilling driver’s cars to own. Packed with pedigree and performance, they command a high price in almost any form if authenticity can be proven. In the UK, a company called Sytner has been responsible for bringing these rare performance specials to market. This 1984 5-Series – called a B9 in Alpina-speak – is listed here on eBay UK with all the right documentation boxes checked.

To understand the significance of an Alpina car requires appreciating just how thoroughly these vintage BMWs were worked over. The B9 took an ordinary E28-chassis 5-Series and swapped in BMW’s venerable 3.5L inline-six. Then, Alpina turned its bag of tricks loose: modified cylinder head, high-compression pistons, hotter camshaft, and revised fuel mapping for the the Motronic fuel injection system. Then, custom Alpina bucket seats, wheels, steering wheel and shift knob were all added to the mix. Those bits are worth a small fortune today.

B9 production was limited to 500, and the seller says this is one of 284 RHD cars. The interior, seen here, shows plenty of signs of use, but the originality is what you’re hoping for. The pricey Alpina bits are still present. Tattered cloth can be repaired and an OEM radio can be sourced. The car does run but will need complete restoration, along with repairs to the rear end and driver’s side door, both of which have sustained damage. The trunk badging looks incorrect to me, and finding a “B9 3.5” badge will be a treasure hunt for the next owner.

Believe it or not, this sticker is a huge clue to this car’s authenticity. There’s also the Alpina plaque on the dash, but if you still have doubts, you can rest assured there’s a paper trail for this car somewhere in the Alpina archives. Other challenges will include likely poor storage conditions, as the mold on the back of the rear headrests could indicate. For the BMW faithful, seeing this car preserved and at least benefit from a sympathetic mechanical restoration is what we’d hope for – and to see this classic B9 Alpina back on the roads again soon.