What should I look out for if tempted when buying private?
I would obviously go to my dealers and have them HPI, Service history and warranty check, as well as confirm original spec.
I heard checking the oil was hard work, anymore info on that or anything else please would be welcome?
it must have a warranty as without you can guarantee the Vanos unit will expire 
For a road car ? - I’d buy a standard M3.
m3 cs is a better car and can have a manual shift … CSL is awesome though and the sounds they make are from god’s own sound studio.
I spent ages looking and the only thing I wanted was the BMW premiere warranty (cant remember its proper name) and no dodgy past.
I only do about 8k miles a year and like the fact they are a bit special so should hold its value a little better. The one I’ve seen is HPI clear, full BMW service history and never been modded. Looks fairly mint tbh…Had a new dif in 2008 tho, any idea why that might be?
Why not everyday?
Could I not get a specalist warranty?
Bored of the Lexus?
[quote=jonnyfox]Had a new dif in 2008 tho, any idea why that might be?
[/quote]
I think it’s quite a common fault on the E46 M3’s to have a low speed grinding/knocking noise from the rear diff. I know two people who had the same problem. Seems to be critical the recommended BMW oil is used.
Gra.
I had a CSL for a couple of years - great combination of a road/track car but eventually too expensive for me to run on track and being my only car I didn’t want to drive it hard enough on the track.
I’ve just picked up an E46 M3 for a daily driver, it’s more comfy than the CSL, is realistically just as capable on the road, and still makes a great noise. All this for not a huge amount of money these days certainly when compared to CSL costs at least.
The paddle shift on the CSL is awesome on track (although takes away some driver involvement) but for the road it wasn’t great for me… I much prefer having control of the clutch/gearbox especially when it comes to junctions/roundabouts where you don’t quite come to a halt. My CSL was pretty comfortable, but there are no seat adjustments, so if you don’t like the position, you are stuck.
As with all M3 variants make sure the running in service was completed on time. Other than that as DaveP says. Personally I’d take the CSL over CS or standard car for the noise alone. Took me a while to get used to SMG and with the later SW upgrades it wasn’t too bad but for stop start traffic manual is the best option.
A friend of mine has a CSL and has had a new diff, it happened not long after getting it and he has run it as a track day car since with no problems (about 2 years). He is a bit rough with it as well.
[quote=DaveP]
I much prefer having control of the clutch/gearbox especially when it comes to junctions/roundabouts where you don’t quite come to a halt.[/quote]
Cheers guys all good stuff. The MDCT has this issue as well which the ISF doesn’t,it’s pretty impressive tbh…I could live with it again.
Saving a few pennies Ade 
If it’s about saving a few pennies, then definitely a standard M3 mate…
Picked up my M3 for 12k - 54 plate, 59k miles, FBMWSH.