I own a mk1 fabia vrs and i am looking at getting some upgraded speaker that bolt straight in, what have you guys used and where did you get them from? 

Cheers.

The speakers are riveted in so you will need to drill them out.

 

When you replace them you will need to make (prefreble) or buy and adaptor which fits and also wiring adaptor which allows you to use the oem plug for your aftermarket speakers.

 

The biggest factor here is budget. If you are not planning on doing any deadening or adding an amp dont expect much, if any, improvement over standard. There are very few speakers available which work off very low power (your headunit will produce 10 watts per channel if you are lucky)