Thank you all for your input,
I drove to Bulgaria with my son on Sat 4th and returned Wed 16th, The drive was relatively easy, quick and trouble free (I'll explain later),
As stated I drove UK – France --> Belgium --> Germany --> Austria --> Hungary --> Serbia --> Bulgaria
My satnav (Google Maps) decided to reroute me via Serbia after I stopped for a break just before the border, unknown to me, I followed it blindly as I only checked it just as I stopped (beginning of the rest/break) and continued driving 30 mins later
.
I only realized after I was passing the turning for Romania.
I arrived at the Serbian border Monday afternoon it took about 20–30 mins to get through I then arrived at the BG border Monday evening and passed through in about 5 Mins, the BG border person was so helpful, he even took me to the machine to pay for my Vignette and explained it to me in a polite way, overall it was a very good experience.
We arrived at our campsite of choice and enjoyed the week there before returning home.
As Serbia was such an easy process and fast, I decided to go Via Serbia for my route back, I was stuck on the Serbian border in traffic for 8 and a half hours! I ended up driving for a continuous 16hrs trying to find somewhere to stop! (all stopping places were rammed). I ended up stopping and getting rest for only 3hrs, it was an exhausting 48hrs. Not to mention, my Aircon compressor on my car decided to fail in the massive que! The heat was 36 deg c, and we were suffering from heatstroke! nonetheless once we were through that we enjoyed the drive but decided on not spending the couple of days we had spare roaming Europe and headed home.
Rough Stats.
Fuel - £510
Miles Driven - 3860
Tolls - £55.69 (Serbia cost about 50% of this)
Ferry - £282
Was it worth it? YES! We both saw some amazing things (check out the road Route 34 in Serbia on the Danube river) and had a great father and son experience.
Will we do it again? Not unless it's Essential, it was a demanding drive for me solo, and I consider myself a very experienced driver.
I hope this helps someone, and if you got any questions please feel free to ask, I will answer what I can.
Carl