SRS - Often seen embossed on the dash and on your steering wheel, SRS stands for Supplementary Restraint System or, in simple terms, the airbag. Designed to work with a seatbelt system in place, hence the 'supplementary'.
BHP/PS/KW - Brake Horse Power is a unit to describe engine power. It is an old motoring term. It describes a method of comparison of an engine to an actual horse. The higher the number the more 'power' your car has. Generally the ratio of bhp to the lightness of your car determines how fast it will be. So lots of bhp and lightweight equals speed.
PS - Often European carmakers will use PS instead of bhp but they mean the same thing, really. PS doesn't stand for postscript but Pfedestarke (of course)!
KW - Is another way European carmakers in particular describe engine output. The unit is always more modest looking as, for example, 100kw actually equals 134bhp.
Torque - The engine's strength described in units of 'Nm' or Newton metres. It is a twisting force and, unlike bhp, which really equals how fast a car is, torque is more significant a measurement in diesel engines. Like bhp, the bigger the number the better.
Adaptive Headlights/AFL - First used in the 1955 Citroen DS, these are headlights that turn with your steering input, or sometimes just additional side lights that illuminate a wider area than your standard conventional dipped headlights when turning. Handy in rural areas and at junctions for seeing paths and other obstacles.
Bluetooth Connectivity - This is a wireless connection to your phone by your car's stereo. It allows you use the phone handsfree and often play music from your phone through the car's stereo also.
CVT/DSG - CVT is a type of automatic gearbox that uses just one variable gear to move the car along. It makes a unique whine and most Electric cars and hybrids use this type of transmission because it is efficient. Motoring journalists hate CVTs (aka Multitronic) because of the racket they make whereas most journos love Volkswagen's DSG! DSG is an automated manual gearbox. Confused? In simple terms you drive it like any automatic with two-pedals but under the bonnet it preselects the next gear to make smoother changes. DSG is an expensive option on VW group vehicles but worth it.
ECU - When a mechanic mentions the ECU - you should take a sharp intake of breath! It is the car's electronic brain and expensive to replace. ECU stands for Electronic Control Unit.
4X4 - 4 for four wheels and 4 for all four wheels are driven by the engine - and not the usual two. Permanent four-wheel drives (aka AWD) use more fuel than conventional two-wheel drives. Some SUVs and Crossovers use a part-time (aka on-demand) four-wheel drive set up that drives the car in two-wheel drive mode until it detects slippage and then it engages power to all four wheels. These are far more economical on fuel but less capable off-road.
DPF - Diesel Particulate Filter is a device that burns off nasty emissions (particulates) from a working diesel engine. Expensive to replace and often targeted by thieves despite the DPF being part of the exhaust system, these devices are essential to reduce nasty emissions. To work effectively they need to get up to temperature and often short trips do not allow this to happen - that's why a good run on the open road is recommended now and again to work the DPF effectively.
Efficient Dynamics - A BMW term to describe a combination of fuel-saving devices fitted to the German carmaker's vehicles, such as brake regeneration, auto stop/start, aerodynamic changes and low rolling resistance tyres. The result is reduced CO2 and fuel consumption. Other car firms will have their version of ED like Ford's ECOnectic label.