The use of gauges is a must on a modified 1.8T.  Especially a boost gauge.  Not only is it cool to see the boost rise but it is a great device to troubleshoot any problems that may be causing a loss of power.  Other popular types of gauges are oil pressure, oil temperature, air/fuel ratio and exhaust gas temperature.

Prices range from $50-150 depending on the sytle and type of gauge.

Links for more info on Guage installation:
http://www.geocities.com/__mongrel__/gti/gauge_install.htm - fastgti1@aol.com
http://www.hscanlan.com/boostgauge/ - harry@hscanlan.com

Here are various pictures of gauge installs: (click for bigger pic)

http://www.pages.drexel.edu/~aka24/guages_pic1.jpg
http://www.pages.drexel.edu/~aka24/guages_pic2.jpg

If you have a picture of your gauge install and would like to add to this page please email me, 18turbo@jwelty.com