Better safe than sorry

So my partner and I are thinking of buying a camper van together however it's a lot of money and like all vehicles can only be registered in one name. Does anyone know how we can protect ourselves if he died or we split up and I give him my share of the money or vies versa how would I get my money back would a letter agreeing what would happen to each other's share be legal or can we get something drawn up by a solicitor? Some advice would be greatly appreciated

The registration document V5 is only proof of registered keeper of the vehicle not proof of ownership so the fact that it will be in your partner's name is not important. For proof of ownership you need a receipt from the purchase showing that it was sold to both of you and your individual contributions, my now husband and I bought a car this way before we were married it didn't cause any problem at the dealership they just took a payment from each of us and named us both on the receipt they specified joint owners as we thought this might be important if one of us died but we didn't check that legally just assumed it would revert to the survivor.