[Steve_c]

Power full enough to stop freezing in the back of a Transit.

Oil Filled Radiator, 500w Single dial control with 6 settings.Anti-frost protection.Size (H)38.2, (W)33.5, (D)17cm.
 I think it should be ok.

[Mist A Bit]

i think any oil filled rad on the lowest setting will do the trick. mines only in an escort van and the rad is very low powered but it works. if the temp is 1 above freezing you`ll be fine