JEREZ, Spain - An innovative rear suspension on McLaren's new Formula 1 car, first seen here during testing, has intrigued rivals amid talk of the team having a potential secret weapon.Ferrari's technical director James Allison told reporters after McLaren's Jenson Button topped the Day 2 time sheets:"I haven't seen it in the flesh but I'd like to see a bit more of it because it does look interesting. I've just seen some blurry pictures on websites."Former F1 designer Gary Anderson, writing a technical analysis for Autosport's website, said the concept should give more downforce at low speeds, reduce drag at high speeds - and appeared legal.HIGH SPEED ADVANTAGE?Anderson said: "This makes it a double whammy, giving you more downforce under braking and in slower corners and less drag at high speed. This could be McLaren's secret weapon because, if it works, it is not something that can be copied in five minutes as it depends on a number of design parameters at the rear of the car."F1 is going through major changes in 2014, with a new V6 turbo unit and complex energy-recovery systems. At the same time changes have been introduced that limit aerodynamic downforce with lower noses and smaller rear wings and tighter controls on exhaust exits. Stay with Wheels24 for the 2014 F1 season – fresh reports every day.