If the car is spending long periods parked outside doing nothing then I would argue the annual service is more important than ever. The garage will replace the oil and oil filter and check the lights, tyres, bodywork and exhaust. The steering, suspension and fluids will also be inspected, along with the brake fluid (which needs to be changed every two years or if there are signs of contamination by condensation).

It's also worth noting that a car with a full a service history is always more desirable than one without.