BMW will expand the M3 range in 2008 with a saloon and a coupé-cabrio, and we’ve caught them both undergoing final tests. The biggest issue in the process of turning the 3-series convertible into an M3 is weight. Because of the extra reinforcement needed to make up for the lack of a roof and the weight of the roof motors and folding mechanism, a 330i convertible weighs a considerable 235kg more than a 330i coupé. But despite some advanced weight loss techniques (such as a V8 engine that at 202kg weighs less than the six-cylinder it replaces), an M3 coupé is just 6kg less than a 330i coupé. It is unclear how BMW will be able to cut the convertible’s 1780kg kerb weight, which rises to a hefty 2130kg when laden. Cutting weight will be less of an issue with the saloon, as in 330i guise it weighs 1555kg, 16kg more than an M3. The styling of both cars is a mix of M3 and regular saloon and convertible. Both use the M3 coupé’s front end, while the cabrio retains the standard car’s rear. At the rear, both cars get four tailpipes, and the saloon gains a discreet lip spoiler on the boot lid. Wheel arches are flared to accommodate the M3’s wider tracks, and the cars also share the same styling around the exhaust and rear valance. We’re expecting the two cars in 2008 — the saloon in March and the cabrio in September, to tie in with the Geneva and Paris motor shows. There are rumours of a possible M3 Touring, though BMW hasn’t confirmed such a car. Audi’s success with fast estates prompted BMW to make an estate version of the current M5, so it may be tempted into trying the same idea with the M3. We certainly hope so.It’s also possible that all future M3 variants, not just the coupé, could get the lightweight CSL treatment. A stripped-out CSL coupé is being rushed to market, possibly as early as the end of 2007, but the boss of BMW’s M division, Gerhard Richter, has hinted that the other body styles will also be offered in the lighter, more focused form.