A custom BMW 1 Series Convertible combines the compact proportions of the E88 with a V8 engine borrowed from a contemporary M3, creating a performance car BMW M never built. Originally a 120i Convertible, the heavily modified car takes an unconventional route to 1M-inspired performance and is now offered for sale at £56,500, or about $75,300.

How the BMW 1 Series Inspired the 1M and M2

The BMW M2 is often viewed as the spiritual successor to the original E30 M3. As modern M3 models have grown to the size of older M5s, the smaller M2 has taken on the role of BMW’s sport compact coupe. Although it is larger than the original E30, it remains relatively compact by today’s standards.

The M2’s roots can be traced to the original BMW 1 Series, which initially launched as a hatchback before a coupe joined the lineup. BMW M used the N54 turbocharged inline-six from the 335i as the foundation for the 1M, increasing its power and adding a unique suspension setup and wider fenders.

The result was the BMW 1M, a model that would eventually pave the way for the M2. However, BMW offered the 1M exclusively as a two-door coupe, leaving enthusiasts who wanted a different body style without a factory-built alternative.

BMW Never Built a 1M Convertible

Buyers looking for a faster 1 Series in another body style had the 135i, available as an E87 hatchback or an E88 convertible. BMW never produced a factory 1M hatchback or convertible, although both could have offered an alternative to the coupe.

Enthusiasts have since modified 135i models to replicate the 1M’s performance, adding power and making other changes. More ambitious projects have gone further by installing the S65 V8 engine from the E90/E92 M3 into the compact coupe.

This latest build takes that approach in a less common direction. Rather than starting with a 1M coupe, its creator transformed an E88 1 Series Convertible into a 1M-inspired machine and then added a V8 from a contemporary M3.

A BMW 120i Convertible With an M3 V8

As reported by PistonHeads, the unusual project stands out among modified BMW 1 Series Convertibles. Most V8-swapped 1M builds have used coupes, with hatchbacks appearing occasionally, making the convertible an unconventional starting point.

The car began life as a 120i Convertible, a choice that adds complexity to the conversion. Convertibles generally lack the structural rigidity of fixed-roof cars, and the E88 was not designed to accommodate the substantial power or engine configuration of a V8 swap.

Nevertheless, BMW M has previously built performance convertibles, demonstrating that an open-top body does not automatically rule out a high-performance model. This particular project, however, pushes the original 1 Series Convertible well beyond its intended configuration.

BMW 1 Series V8 Convertible Is Listed for $75,300

Starting with a 135i Convertible might have made for a more straightforward tuning project, but this build takes a more unusual approach. Its combination of a convertible body, 1M-inspired modifications and a contemporary M3 V8 gives it a distinctive place among custom BMWs.

The one-off BMW is currently for sale for £56,500, equivalent to about $75,300. Although faster cars can be purchased for less, this unusual 1 Series Convertible offers a combination of modifications and body style that sets it apart from more conventional performance builds.