I have carried full coverage on at least 3 cars (as many as eight) since Nixon was in the White House and have never had a single claim... not one!
Yea... it irks me to write the check, but then again, I have been well covered. The fact I've never used it didn't diminish the security it provided.
My Boxster is on specialty insurance, - Liability + Agreed Value. Mileage limited to 5k/yr.+carryover (which I've never come close to exceeding - own 4 other cars between 2 people, and I office from home - no daily commute) - annual premium $244.
I do have a mid-'90's SUV (the 'Mule') which has less than 100k on it and is still in excellent shape both mechanically and aesthetically - have spent less than $50/yr. on upkeep the past 5 yrs. It's used through the winter and as the hauler. 2 yrs. ago I dropped the collision because the market value for it is essentially non-existant. I couldn't get $500 for it today, but it's worth much more than that to me. But that's the only car I've ever, or would ever, consider not having full coverage for.
IMHO, carrying limited coverage on a Boxster is the essence of 'False Economy'. If it's not a DD, consider looking into specialty coverage instead of dropping full coverage.
You may say you've saved $10k - $20k through the years, and undoubtedly you may have, but that is in no way a raving endorsement of your practice. In reality you've
only been lucky... but others may not be. Proper insurance mitigates reliance on luck.