ok.. one by one...
oil change n flush... ok... if ur CLK is produced by Perodua... then its same steps n procedures... but if ur CLK is produced by Mercedes... then i would recommend u to send back to the authorised SC.... i heard it is diff to service a Merc...
for spark plug, get de spark plug wrench from hardware shop or sparepart shop... make sure u tell them ur car model as diff car model got diff size...
oil filter wrench - can get from hardware shop or acc. shop... shoping mall also got... got a few types... i use de cheapest.. hehe...
air twister - made of 3" PC fan blade... center part cut a hole to eliminate unnecessary air restriction... stuff into de rampipe... u may use double sided tape (foam type) to secure it if it is loose...