Four hundred catalytic converters have been stolen since January 1 in parts of Cambridgeshire.
Police revealed the bulk of the offences have taken place in East Cambs, Huntingdonshire, Cambridge City and South Cambridgeshire.
Over the past week thieves have targeted vehicles parked in the Trumpington, Madingley and Longstanton Park and Ride sites, together with the Queen Anne car park in Cambridge and the car parks at Addenbrooke’s Hospital.
In just one week 23 catalytic converters were stolen from car parks.
Detective Chief Inspector Alan Page said: “This type of crime is extremely disruptive for the victims, and it is particularly despicable that these individuals have targeted cars at hospital car parks where people are attending for appointments or to visit a poorly relative or friend.
“Targeted patrols by dedicated officers are taking place, but we also need the public’s help.
“We would like to hear from anyone who was at any of those locations in the past week and may have noticed any suspicious behaviour or vehicles.
“We would also like to hear from anyone who may have information about who is stealing catalytic converters and where they are being sold.
“These offences are taking place in broad daylight. If you are using a public car park, business car park or a Park and Ride site please be aware of people jacking up vehicles or laying underneath them with a running vehicle parked nearby.
“Call us on 999 with descriptions of those involved and the make/model and registration number of the vehicle they are using.”
Catalytic converters are found in the exhaust system of every car and reduce the output of toxic gases and pollutants.
It takes just minutes for thieves to remove them and on many occasions, victims are unaware initially until starting their vehicle that they have been targeted.
To keep your catalytic converter safe, you can ask your car dealer for advice on locks or guards that are approved by the vehicle manufacturer and tested to Sold Secure Gold.
Alternatively, try to make sure your vehicle is parked in a garage overnight, or if you have a commercial vehicle, park it in a secure compound.
If this isn’t possible, park in an area that’s well-lit and overlooked and try to park so that the converter can’t be easily reached by potential thieves. Vehicles that sit high above the road are particularly vulnerable.
You should also register your converter and mark it with a forensic marker, which will make it harder for thieves to dispose of.
In recent months, Cambridgeshire police has marked the catalytic converters on around 200 vehicles so they can be identified if stolen and sold on.
For more information about catalytic converter thefts, visit the force’s dedicated web page.