How many ignition coils are there on a 2002 volkswagon beetle turbo.  I took my car to a repair shop and they said I need for new ignition coils and  a new vacuum advance valve 

First check the oil level. pull out dipstick with engine off, wipe, and re-"dip" it to see . If the level is O.K., it may be serious . See a mechanic.

is it gas or diesel?

Switch in sealt belt latch probably has gone bad.

Overheating.

First one is 17978 -ECM blocked By Immobiliser. there is something wrong with car key or imobiliser. try with second key. If problem presist, go to diler on diagnostic tool. all the rest are for glow plugs. change them.

Hope it helps
Marko

Have the alternator tested. Repair or replace if bad.

vw uses coil on plugs so each plug has a coil under engine cover on top of valve cover check fuses first for your other problem

Bentley Publishers is one option.

Volkswagen New Beetle Owner's Manual: 2002 by Volkswagen of America
4-ring binder, 9 1/4 x 6 3/4 in.
over 370 pages
Bentley Stock Number: RB02
VW Part No. WSA221557BEE23
ISBN-13: 978-0-8376-0851-8
Price: $49.95

The switch in the trunk which tells the alarm that the trunk lid is closed is either defective or not correctly adjusted. If this info is of no help to you, than you don't know enough to fix it. Take it to a reputable VW shop for repair.
Charlie

i would get a haynes manual. it should tell you how to change it out step by step