Guys,

I am getting itchy fingers to try my hand at selling a few budget (but respectably decent) motors but need some help from anybody in the know.

Basically, I like and know my cars but have not had to sell many before and I need to get an idea if I need to register / set up a business and what responsibilities I would have buying cars in (do I declare to any private seller I am a dealer) and what would I be required to do on the sale e.g. offer any sort of limited warranty?

I don't want to be on the shady side of right and intend to start properly with a view to having a few cars at any one time bought in for between £500 and a grand hoping to make a few £100 on them each.

I suppose for the first few I could buy and sell as 'private' but I would not be able to keep that up surely? I guess when it become 'serious' you would have to start tax returns etc...

I am not looking for this to become my main income (unless I am genius at it!), more some spending money / something to possibly get me through an impending redundancy.

ANY help or comments from experience appreciated.

(any "ooo, wouldnt do that if I were you" gained from nothing more than an evening down the local please keep to yourself - ta.)

Legally: you need traders insurance (or to insure each individual vehicle) and must do Tax Returns Annually!

What you actually do is up to you  As above, PM Josh... He's a young lad who set up a little while ago and I'm sure he'll be willing to give some pointers

A few pointers as mentioned;
Motor trade road risks policy is of paramount importance. If you don't have this, you can't work properly. Mine costs £5000 for the year, but that's due to age and the fact I have unrestricted engine capacity and high value vehicles etc.
It may cost you £900 to £1200 for a decent policy. Give Tradex a call, they're the best in my opinion. You will need to have 'demonstration cover' aswell.

Trade plates, these are also a must. Currently cost £90.75 for 6 months. These can be difficult to obtain, but without them you can't operate properly and safely. Trade plates in essence are a portable tax disc which you can transfer from vehicle to vehicle, but they are only for business purpouses. As in, taking a vehicles from place of purchase to sale, to repairs, fuel station. You won't be able to 'run round' on trade plates.
Local authority and covenant appurtenant issues should also be considered.

Currently I have a mixture of vehicles. I tend to avoid sub £1000 vehicles unless they are Omega's or p/xes.
I have a 2001 Focus, 2005 Touran, 2002 Bentley, 2007 Range Rover, 2003 Omega V6 Special, 2005 Focus, 2010 Fiesta, 2007 Fiesta, 2005 Sprinter 316 MWB, you can specialise or have a mixture. But, don't do what I sometimes do, and buy a vehicle because you like it.
You need to have space to store the vehicles as Chris says and enough capital for a 'just incase'. If you lose £700 on one vehicle, will that cause issues for you?

Legally, as a motor trader, car dealer whatever you want to call it there are certain things you need to take note of.
You will see plenty 'sold as seen' adverts...this is utter crap you can't sell a vehicle sold as seen as a trader with only one exception.
If I have a known defective vehicle, say an Omega with a blown oil cooler and I list it as 'sold as seen' this means I have the intention for it to be only sold to other traders, not regular customers. So you can't sell known good vehicles sold as seen.
You have an obligation legally for a short time (3 days) after the date of sale as set out in Thrane v Mitchell (PM for case law) to rectify any issues in a reasonable time or then offer a full refund.

Example,

I sell a 2006 Range Rover. In my custody the air suspension operates correctly and I am aware of no defect with the system. After 2 days the system fails and requires repair. I am legally obliged to offer to repair the vehicle at my cost, but in a reasonable time...so they can't demand it's done straight away.
If the engine blows up, I an legally obliged to either repair the vehicle or offer a full refund.

If the vehicle was subject to unusual stress, as in had competed in a time trial race etc than my liability is fully discharged and I am not required to repair the vehicle (unless of course the vehicles sold is a race car)

The worst thing is people 
You will get some morons, and some very nice genuine people. Some people complain about everything, some people actually understand and are very good and reasonable. In 99% of cases sales will go fine, but there's always the 1% lurking.

Please feel free to PM me or give me a call if you have any questions 

Been doing a bit lately myself, mainly cars people need shut of or have failed MOT's and a couple of auction buys. Been quite fortunate and had a couple that have earned up to £1000. Mainly doing it for extra income but it also keeps me out of the pub!

Will get a trader quote as it's a real pain in the ass adding cars to my current policy for a week at a time, Good luck mate