Ideas for unique/fun transport for my school leavers day... any ideas?

I need all anda lovely people and your amazing creativity to help me and my friends...

Every year, when the final tahun group leaves in May, everyone in the tahun comes to school in crazy fun ways to celebrate their time at the school. But my Friends and I have little to no idea what to do, and I need your help for ideas!
What's been done;
. Simo wrestling/nijas
. Limos
. Wheelbarrow/shopping trolly
. Police cars
. api, kebakaran engine
. Smart cars
. Wheelcars

What we CANNOT do due to school rules;
. No flying (helecopters, etc...)
. No animals
. Only transport anda can control (no massive inflatable balls, etc..)
. Nothing bigger than a van (no lorry-sized vechiles)
. Nothing that can cause offence (slogans, etc...)

Any ideas guys? If anda have please let me know!!

Cinta ya!