Verdict
A
Aston Martin Vulcan — spec data and generation history.

Track-only hypercar — One-77-derived 7.0 V12 NA (820 bhp), six-speed Xtrac sequential, full carbon body, no road registration. 24 cars built, all sold to existing Aston customers. Inboard pushrod suspension, four-way adjustable dampers, switchable power modes (500/675/820 bhp) so customers could build up to the full 820 bhp tune. RML later offered a 'AMR Pro' upgrade and one-off 'Vulcan Road' conversions — the most outrageous post-factory Astons ever made.
Click any generation for the full deep dive

7.0 V12 NA — 820 bhp, 0-62 in 2.9s.
Common faults reported on each generation — useful when shopping the used market.
Aston Martin One-77 · Ferrari FXX-K · McLaren P1 GTR · Pagani Zonda R