The European Fiat 500 is available with an optional fixed glass roof or power sliding panoramic roof called a Skydome. With either version, the sheet metal in front of the roof is glossy black and blends in with the roof to make for a smooth appearance.
The fixed glass roof is about 5 mm thick with a light transmission of 16% and energy transmission below 19%.
The sliding roof has a thickness of 4 ± 0.2 mm, light transmission of 19 ± 2 % and an energy transmission of less than 19 %. The roof has an opening/closing time of 5 ± 2 secs.
A sunshade is provided to adjust the light intensity inside the car. It is manually operated on cars with fixed glass roofs or opened and closed electrically on cars equipped with the sliding roof.
In cases of emergency or maintenance, it is possible to open/close the glass panel manually by removing an access plug and using a provided crank.
Additional safety and technical specifications
Fiat designed the sun roof to meet a very stringent criteria, guaranteeing that it can handle even the most demanding operating conditions. Here are some interesting facts:
The raising of the front panel (due to the aerodynamic effect while moving) towards the outside at a top speed of 113mph (180 Km/h) is less than or equal to 2 mm.
The stresses on the roof panel measured/calculated while driving over cobbled streets does not produce vibrations or noise that adversely affect driving comfort. If the sun roof has to be closed manually using the emergency key, the force required (tightening torque) is less than or equal to 8 Nm.
The bonding of the rear glass section is technologically treated like a windshield, not allowing water penetration into the passenger compartment under any circumstances.
Source: Fiat Auto SpA