Tha Calum Iain agus Louise anns a' Mhonadh Ruadh an seachdain seo airson a' chiad Dùbhlan Soapbox. 50 mìle gach uair ann an cartie - a bheil iad craicte? Tha Calum Iain a' sgrùdadh an Tesla Roadster dealain - a bheil e gu dearbh nas fheàrr na càraichean peatroil? Calum Iain and Louise are in the Cairngorms for the first ever Soapbox Challenge. 50 mph in a cartie - are they mad? Calum Iain puts the electric Tesla Roadster through its paces and asks if it can really beat its petrol rivals.