You can buy after market dipstick (about $50.00 with shipping) that will check your oil level. Plug is located on fire wall passenger side. Dipstick is only used to check oil level, you have to remove it and replace with the plug. Mercedes Benz dealers change oil from dipstick using an engine oil extractor (from $20.00 to $100.00). Use only 0w40 mobile 1 $7.00, use fleece filter by Mann Filter $13.00. I change my oil every 10,000 miles. Total oil change with oil filter under $70.00. I use K&N Air filters last 100,000 miles. Air filters $30.00 to $50.00 one time charge. Reusable air filter with recharger kit K&N 99-5050 about $10.00. Uses recharger kit every 10,000 miles.