Buying advice for M5

[mpg]

Hope someone can give me some ideas as to what to look for in buying a late 90's M5. My brother is considering this or the XJR as an option for forthcoming parenthood(the Audi TT is no good).I have an XJR and I know about some of this cars pitfalls such as Nikasil lining on cylinders and timing chain tensioners but are their similar type problems to look for in M5's of this age.Any advice is most welcome. Personally I would like him to get an M5 as I've never driven one

[mpg]

Yes sorry its the E39 I was after info on I'll do a search about the VANOS if thats the only concern. Cheers