corrosion from winter road de-icing materials. In any case, for general registration all functional safety equipment should be operating – turn signals, brake lights, headlights, horn, etc. The windshield should have no running cracks (small stone chips and "stars" may be acceptable if not in the driver's principal line of vision). If the vehicle has been reconstructed from a salvage vehicle (a vehicle whose registration has been forfeited) inspection may be more severe to ensure compliance and the legitimacy of sources of salvage components by presentation of proper purchase receipts. Registration procedures will vary by state and will usually be more difficult in states with strict emissions requirements. On the other hand, changing the registration allows a conversion to qualify for tax incentives available in some states, such as Oregon, for either the vehicle, the charging system, or both. California (US) conversion registration and taxation The State of California makes provisions to inspect electric vehicle conversions. Electric vehicles are exempted from emissions control inspections. A vehicle may either a substantially new build, or a conversion of an existing vehicle. Spain In Spain, the conversion (called transformation) is regulated by Real Decreto 866/2010, de 2 de julio, por el que se regula la tramitación de las reformas de vehículos. See also Aftermarket (automotive) CalCars Conversion to sleeper car Electric car Engine swap Green tuning Kit car Maker culture Plug-in hybrid (PHEV) Vehicle glider References Electric vehicles Green vehicles Plug-in hybrid vehicle industry