Peckforton is a great venue we did our first one when we had our Evoque, we are there next month as we now have a Discovery 4. Try and get a deal with dinner and breakfast in the Castle, the night before your Experience.
Mine also turned up in the post about three weeks after getting the car and I have had two reminder emails this week. I was thinking of going to Luton Hoo as it's just down the road but after hearing all the feedback on Peckforton may look into it further! Love the excuse of dinner b&b in a castle!!
My car was 6 months old when I purchased it and the dealer organised the half day LR Experience voucher (which has no time limit ) without being asked. I didn't even realise that they did these Experience events until the dealer told me and gave me the voucher!