Could someone correct these for me and maybe help with the last one, i got completely lost on it!

Arka - behind

arkası - behind something

arkamda - behind me

arkanda - behind you

arkasında - behind him/her/it

arkamızda - behind us

arkanızda - behind you (plural)

arkalarında - behind them

Karşı - opposite

karşısı - opposite something

karşımda - opposite me

karşında - opposite you

karşısında - opposite him/her/it

karşımızda - opposite us

karşınızda - opposite you (plural)

karşılarında - opposite them

ön - front - ???

bir şeyin önünde-in front of something

önümde-in front of me

önünde-in front of you

onun önünde-in front of him/her/it

önünüzde-in front you(plural)

önümüzde-in front of us

onların önünde-in front of them

I´m not sure on this one, could someone help me make it like the above, ie. making it in front of something, in front of me, in front of you etc.

Any help would be greatly appreciated, şimdi teşekkür

Arka - behind

arkası - behind something

ı 

 Could somebody explain this to me as I am a little confused . I thought that behind ( a thing )  was shown with  arkasında not just arkası

Arkasında . Like arabanın arkasında - behind the car  

many thanks

 "arabanın arkasında- behind the car" is the correct one. "arabanın arkası" means "back of the car"...