Insurance companies are changing their insurance rates all the time. Sometimes they raise them when there have been a large number of claims, and sometimes they lower rates when they are looking to pick up more clients. What all of this amounts to is that a cheap policy might just represent a market shift or a change in the needs of a particular company. In other words, don’t just give the hairy eyeball to all cheap rates; seek them out. Just make sure that the policy represents your needs well.
Another important factor in determining car-insurance premiums involves the annual mileage put on the vehicle, and for what reason. Driving to and from work every day at a specified distance, especially in urban areas where common traffic routes are known, presents different risks than how a retiree who does not work any longer may use their vehicle. Common practice has been that this information was provided solely by the insured person, but some insurance providers have started to collect regular odometer readings to verify the risk.
Those not exempted from obtaining insurance must obtain a certificate of insurance from their insurance provider, and display a portion of this (an insurance disc) on their vehicles' windscreen (if fitted). The certificate in full must be presented to a police station within ten days if requested by an officer. Proof of having insurance or an exemption must also be provided to pay for the motor tax.
In 1998, the Progressive Insurance company started a pilot program in Texas, in which drivers received a discount for installing a GPS-based device that tracked their driving behavior and reported the results via cellular phone to the company. The program was discontinued in 2000. In following years many policies (including Progressive) have been trialed and successfully introduced worldwide into what are referred to as Telematic Insurance. Such 'telematic' policies typically are based on black-box insurance technology, such devices derive from a stolen vehicle and fleet tracking but are used for insurance purposes. Since 2010 GPS-based and Telematic Insurance systems have become more mainstream in the auto insurance market not just aimed at specialised auto-fleet markets or high value vehicles (with an emphasis on stolen vehicle recovery). Modern GPS-based systems are branded as 'PAYD' Pay As You Drive insurance policies, 'PHYD' Pay How You Drive or since 2012 Smartphone auto insurance policies which utilise smartphones as a GPS sensor, e.g. . A detailed survey of the smartphone as measurement probe for insurance telematics is provided in 
The registration number of the vehicle shown on the insurance policy, along with other relevant information including the effective dates of cover are transmitted electronically to the UK's Motor Insurance Database (MID) which exists to help reduce incidents of uninsured driving in the territory. The Police are able to spot-check vehicles that pass within range of automated number plate recognition (ANPR) cameras, that can search the MID instantly. It should be noted, however, that proof of insurance lies entirely with the issue of a Certificate of Motor Insurance, or cover note, by an Authorised Insurer which, to be valid, must have been previously 'delivered' to the insured person in accordance with the Act, and be printed in black ink on white paper.
Several Canadian provinces (British Columbia, Saskatchewan, Manitoba and Quebec) provide a public auto insurance system while in the rest of the country insurance is provided privately [third party insurance is privatized in Quebec and is mandatory. The province covers everything but the vehicle(s)]. Basic auto insurance is mandatory throughout Canada with each province's government determining which benefits are included as minimum required auto insurance coverage and which benefits are options available for those seeking additional coverage. Accident benefits coverage is mandatory everywhere except for Newfoundland and Labrador. All provinces in Canada have some form of no-fault insurance available to accident victims. The difference from province to province is the extent to which tort or no-fault is emphasized. International drivers entering Canada are permitted to drive any vehicle their licence allows for the 3-month period for which they are allowed to use their international licence. International laws provide visitors to the country with an International Insurance Bond (IIB) until this 3-month period is over in which the international driver must provide themselves with Canadian Insurance. The IIB is reinstated every time the international driver enters the country. Damage to the driver's own vehicle is optional – one notable exception to this is in Saskatchewan, where SGI provides collision coverage (less than a $1000 deductible, such as a collision damage waiver) as part of its basic insurance policy. In Saskatchewan, residents have the option to have their auto insurance through a tort system but less than 0.5% of the population have taken this option.
Insurance companies have started using credit ratings of their policyholders to determine risk. Drivers with good credit scores get lower insurance premiums, as it is believed that they are more financially stable, more responsible and have the financial means to better maintain their vehicles. Those with lower credit scores can have their premiums raised or insurance canceled outright. It has been shown that good drivers with spotty credit records could be charged higher premiums than bad drivers with good credit records.
Vehicles kept in the UK must now be continuously insured unless a Statutory Off Road Notification (SORN) has been formally submitted. This requirement arose following a change in the law in June 2011 when a regulation known as Continuous Insurance Enforcement (CIE) came into force. The effect of this was that in the UK a vehicle that is not declared SORN, must have a valid insurance policy in force whether or not it is kept on public roads and whether or not it is driven.
Some classes of vehicle ownership, or use, are "Crown Exempt" from the requirement to be covered under the Act including vehicles owned or operated by certain councils and local authorities, national park authorities, education authorities, police authorities, fire authorities, health service bodies, the security services and vehicles used to or from Shipping Salvage purposes. Although exempt from the requirement to insure, this provides no immunity against claims being made against them, so an otherwise Crown Exempt authority may choose to insure conventionally, preferring to incur the known expense of insurance premiums rather than accept the open-ended exposure of effectively, self-insuring under Crown Exemption.
But liability coverage levels come in threes — you’ll probably see something like 50/100/50 up to 250/500/250 in typical policies. You can think of these limits like: individual injuries / total injuries / property damage. Insurers are a little more technical, calling them bodily injury liability, total bodily injury liability and physical damage liability.