Following the original LF-A concept, development time was lengthened by the switch from an aluminum frame to a carbonfibre tub, the result of engineering efforts aimed at improving the LF-A's power-to-weight ratio. The LF-A was reported to draw engineering resources from Toyota's Formula One team. In January 2007, a restyled LF-A concept car premiered alongside the first production F marque vehicle, the IS F sports sedan. The second LF-A concept featured a more aerodynamic exterior, a near-production interior, and F marque emblems. Later that year, Lexus Great Britain director Steve Settle indicated plans for a V10 and hybrid version of the LF-A. The hybrid version, combining a petrol engine with electric motors, was to feature a V8 powertrain similar to that designed for the Lexus LS 600h L. LF-A test mules continued to be spotted at the Nürburgring, including early models with a large, fixed rear wing. In December 2007, "Auto Express" reported that the LF-A had set an unofficial 7:24 lap at the Nürburgring.