Need some advice whilst buying a car (for towing?)

Yes you would because the kerb weight is 200 kg less, meaning that you would have to go for lighter caravans which tend to be smaller.

My advice would be to find a caravan that you like and then identify a car to tow it based on the MPTLM of your caravan, which might need to be heavier than either of the cars that you have identified.

I haven't read the regs in detail for some time. Does the 3500Kg refer to gross train weight as the car may well weigh more than the kerb weight when loaded. Is the figure not the two maximum weights quoted in the plating?

Try this, Alex.

https://www.caravanclub.co.uk/advice-and-training/advice-for-beginners/driving-licences/

I agree with your theory & would go for the estate rather than the hatch. You could always take your B&E part of your test  ..... but I appreciate that's easier said than paid for. 

Remember that it is not the actual weight of car and van but the max permitted weights.

Our X-Trail has a weight of 1725kg but max laden weight of 2,200kg. Similarly with the caravan the relevant weight is the MPTLM

Legally speaking the tow car doesn’t have to be heavier than the caravan.    As others have said the 3500kg limit is based on the theoretical weights not the actual weights. 

Thanks everyone for your contributions; they're very helpful. I definitely would like to do my B + E but the cost makes it impossible at the moment.

Example. I have the 2012 Octavia Estate 2.0TDi 4x4, kerbweight 1,495kg plated GVW 2,095kg, towing my caravan with a mtplm of 1,318kg gives a tow ratio of 88%. Also GVW 2,095kg + mtplm 1,318kg = 3,413kg so OK with a B licence.

A couple of other points:

• Be aware of the maximum towbar weight the car can accept.  Many otherwise 'good' cars have miserably low towbar weights which can preclude towing a lot of 'vans that need 80kg or more.
• There is an 85% 'rule' - so called - which states that your car should be at least 85% of the weight of the 'van it is towing.  However, this is a recommendation, it is not the law and is up to your discretion.
• ... which leads up to the fact that, with only a 4 mile tow to do twice a year, assuming the conditions are good weatherwise and there are no steep hills on the route,  in your position I'd be prepared to 'bend' the 85% rule

you can answer your own question really as you already have a caravan so look at the weight plate near the door and subtract the mtplm from the max weight for the car (not the kerb weight) and what's left will be what vehicle you can go for so you are under or near to the 3500kg. plus once your all legal you can venture further afield and enjoy other sites around the UK and eventually Europe. good luck with all your travels.