Warranty-covered repairs as well as recalls should be done at the dealer
That really depends upon the type of spark plugs that are in your vehicle. Vehicles 15 years old or older are more likely to have standard plugs with approximate life expectancy of 12.000 - 15,000 miles. Newer vehicles up to model year 2000 are usually platinum-tipped, lasting approximately 30,000 miles. Lastly, some 2001 and newer models come with iridium-tipped plugs which could last up to 90,000 miles.
For vehicles that are parked inside, car care experts recommend that the wiper blades be replaced at least once a year or when the wiper blades start streaking, whichever comes first. On vehicles kept outside or in areas where the wipers received excessive use, change the blades tow or even three times a year is recommended for clearer vision.