If you are looking for a new exhaust just as a replacement for your car then there are many places to start your search. Most car part fitters such as Kwik Fit should be able to replace your exhaust for you without too much of a wait. Alternatively if you are happy to fit it yourself, there are many suppliers of car parts both on the High Street and online.
If you want to upgrade your exhaust to a bigger and better one, you could be better off contacting a specialist shop such as onlineautomotive.co.uk and asking advice on what would be best for your car and requirements.
It is also important to remember that your car exhaust should ideally produce as few emissions as possible so as to keep pollution levels down in the environment. When you go to buy a new exhaust, or to have one fitted you should try to find out as much as you can from the person in charge to make sure that your new exhaust is as environmentally friendly as possible.