Hi there, haven't needed a lot of parts for my Lag I yet but the bits I have needed came from the local GSF Depot, the chap at my local MOT centre uses them as well. If you do a Google for GSF they do an on line catalogue in PDF format.
If the part is not available aftermarket and you or a friend are visiting France,then buy it there!.Get a written quote with the part number on it from a UK dealership and then quote the same number to any French dealership,you will be surprised at the difference.
GSF are good,as are Euro Car Parts.Both have websites with full catalogues on them,and one of our sponsers on the site(Shop4parts) have a similar service available.
I am currently rebuilding the head on my Laguna. I got the valves and head gasket from CMAEXCHANGE near Chester. Thier prices were good and they have a good reptation for parts suppy and work.
Euro parts in Chester could not quote! - said valves and gasket not listed for my model.
I have ben driving Landrovers for the last 10 years, i am shocked at the prices of parts on my recently purchased Renault. i.e. One rear suspesion bush for a Laguna costs more than the entire set for a discovery.
from experiance, i found a few things cheaper then dealers on ebay and were new ie
new aerial base from deals was 20 plus vat got brand new from ebay for 5.99, also needed a new stalk dealer was 30 plus vat asked if anyone had one on ebay and got one for 15 quid, pitty ebay don't sell new keys would have saved me a bomb lol