I think your greatest chance for success would be to leave the Spridget alone and buy an automatic Miata to park next to it.
You can get an M1 or M2 automatic Miata very reasonably and they are great cars.
My 5 speed (manual trans) M2 Miata is hands-down the best car I have ever owned.
Nial, I thought I saw you with a Lotus 7 somewhere.
I'm hoping my Elan surpasses the Miata. I'm on my second one and really prefer to feel the road in a lighter car. Don't really like power steering or cars that need it but I admit that in most cases we take the Miata.
Kurt.