virtually all are advertised on auto trader so keep an eye there.
Otherwise contact a few indy merc specialists.
usually there are 2 or 3 advertised for sale this time of year, but for some reason its all gone quiet.......
They are few and far between so you may have to be patient.
There are few issues you need to be aware of over and above those of the SL500 but a couple I can think of:
- alloys - 18" split rim AMGs look great but are costly and difficult to refurb if required so bear this in mind. Original alloys, which of course are desirable, are likely to need refurbing as they will be around 10 yrs old by now.
- my first care (P reg) was stolen/recovered - keep an eye out for it - it was silver.
- suspension parts/bushes will need attention - it a big heavy car with firm suspension and low profile very wide tyres.
- check out the underside. Good clean underbody usually suggests a well-pampered garaged car.
- don't buy anything pimped up!
I sold my car to this chap:
http://www.classic-benz.co.uk/index.htm - Andrew Stansfield is the proprietor and he is a very nice, knowledgeable chap.
I know he sold my car on in February but he may be able to help you source another.