2 years into a 48 month deal it but I had amassed £1000 of equity last May when a got my car service
Prices have taken a massive hit since then, I'd be surprised if you've any equity at the moment. Unfortunately.
And it generally takes longer on a 4 year deal to reach the point of equity as you're paying less capital off per month. Prior to the big drops in p/x prices caused by VW's incentives and emissions scandal fallout previous VWs on a 3 year PX saw me in positive equity at around 2 years, likely 3 years before you reach equity on a 4 year deal without a colossal deposit.
*
Assuming 12% deposit (either by discount or money paid) on a £30k R (back in May 2014) and £15.5k* GFV you've got £10900 + interest to pay over 4 years. Chances are you'll have cleared around 15% of that £10900 in year 1 (£1635), the car would've had to be worth £24765 in p/x at 1 year old for you to not be in negative equity on it.
Right now on your 2 year old example, you're probably looking at the car being worth £20k in p/x and you actually owing £22040 (on the assumptions above).
Unless you had close to the full allowable 30% deposit (financing 70% of the RRP from money down and discount) you will be in negative equity.
*Assuming you've got a 4 year GFV of around £15500 (i'm taking an educated guess based on the old GFV of £18500 at 3 years) you're likely to be handing the keys back with zero equity, unless the R's used prices strengthen a lot if/when the VW CO2 scandal blows over.