I read a fiction book around 1970 when I was a kid.  The book was
probably published in the 1950's, but no earlier than the mid 40's. 
It was about a boy who befriended an old mechanic who helped him
restore a MG-T series car(possibly MGTD).

I wanted to reread it just for fun, but can't find it.  Can anyone
help?

-Jason

Hello.

Your book was probably "The Red Car" (1954) by Don Stanford.

See this description from another fan of the book:

"...little book called The Red Car. As an 8th-grader in 1967, I
ordered my 45-cent paperback reprint of Don Stanford’s 1954 novel
through Scholastic Book Services...
The Red Car is the story of young Hap Adams, a teenage boy who lives
on a small ranch just outside the little silver mining town of Bullet,
Colorado. A crashed red MG-TC is hauled to the town’s garage, run by
mechanic and former European driver Frenchy Lascelle; the car and its
resurrection open the door to a whole new world for Hap and his
friends."
source:  Rick Sparks, "The Red Car: The best 45 cents I ever spent" on
web page called "Celebrating BMW 6-Series," hosted by geocities:
http://www.geocities.com/silbersix/sixer11.html


The book is available from  Alibris:
http://www.alibris.com/search/search.cfm?qwork=5601456&ptit=The%20Red%20Car&pauth=Stanford%2C%20Don&pisbn=&pbest=2%2E95&pbestnew=29%2E21&pqty=36&pqtynew=1&matches=36&qsort=p
Or Amazon:
http://www.amazon.com/exec/obidos/tg/stores/offering/list/-/1568497318
Or Abebooks:
http://dogbert.abebooks.com/servlet/BookDetailsPL?bi=222749308

search strategy:
abebooks.com / keywords: mg, fiction

I hope this helps.

THANKS!  I searched for HOURS, and had given up hope.  This is the
first time I had used this service, and I am very impressed!

Thank you for the tip.
-juggler