Car crime in middle-class neighbourhoods is rising, figures have revealed, as police say drivers should buy steering wheel locks and Faraday bags to block radio signals because new vehicles are easier to steal.Research by The Telegraph reveals more than three quarters of investigations into car theft in England and Wales are unsolved and it is new high-tech keyless models being targeted, not older vehicles.Over 78 per cent of car theft cases end with police failing to identify a suspect, amid claims forces are so stretched they don’t have time to properly investigate car theft.In an interview with the Telegraph, the man in charge of crime prevention for the West Midlands force, Mark Silvester, encouraged people to buy steering wheel locks and Faraday bags to keep their key fobs inside to prevent thieves hacking into their vehicles.Keyless models, which have become increasingly popular with middle-class families, provide criminals with a new way of stealing cars by copying the electronic information and conning the car into thinking the key is present, allowing a thief to drive off. Vehicles are being stolen from driveways around the country, but research shows wealthier areas just outside the capital and other big cities have been hit hardest. Earlier this month Dave Thompson, the head of the West Midlands force, admitted his team grades calls based on how vulnerable the victim is because officers are too stretched to attend every call. He told the Financial Times car crime had risen “quite dramatically” and is was affecting mainly middle-class areas. Office for National Statistics figures analysed by The Telegraph show car theft has risen by 30 per cent in three years and jumped 20 per cent in 2017 alone.Between March 2014 and March 2017 the number of recorded car thefts rose from 70,053 to 91,361, hitting levels not seen since 2011. He also suggested people buy an inexpensive Faraday bag to keep their key fob in which prevents criminals from cloning it using radio frequencies. He told The Telegraph: “We know cars are more difficult to steal by conventional means but from what we’ve seen on CCTV captured by witnesses and our own research we’ve got to say it’s a known method of stealing a vehicle using electronic compromise. “This isn’t just unique to more expensive brands, we’ve seen all sorts of cars that have electronic technology on board – we’ve not just seen that with the prestige brands, a lot more run of the mill, volume car manufacturers are being affected in the same way as the prestige brands now.”It can happen anywhere not just at home on the drive at night – a lot of this is software based, we do ask people to be aware of the software updates.” Overall 30 of the 44 forces in England and Wales saw an increase in car theft between 2012/13 and 2016/17 and some of the largest increases were in middle-class areas bordering London.Hertfordshire and Surrey saw car theft increase by more than 35 per cent in the last four years, while Hampshire saw the largest spike in theft since 2012/13, rising 56 per cent.Overall the Metropolitan Police had the largest number of offences in 2016/17 at 26,958 – a 25 per cent increase on the year before.Just 14 forces saw a decline in car theft, with Dorset, Cheshire, South Wales, Lincolnshire and Dyfed-Powys recording the largest falls. Mr Silvester also warned owners to be careful when handing their fob over to valet parking services or car washes, as keys can be cloned “in seconds”, allowing thieves to take the car at a later date without any external signs of damage.His force, the West Midlands, has one of the worst car crime rates in the country – a 39 per cent increase in just one year between 2015/16 and 2016/17, according to the ONS. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.