I tend to use a comparison site, find the cheapest and then go direct to apply but online. Also I find that for example if Im with tesco, when the renewal comes, cancel and then redo on line with the same company. You get a much better deal when re-applying online as your classed as a new customer to them.
I have a 1.9tdi, im 25 in march, my ins is £430 with 4 years no claims bonus.